Systems and methods for signaling profile and level information in video coding

ABSTRACT

A method of decoding video data comprises: receiving profile tier level syntax; parsing a syntax element, from the profile tier level syntax, indicating a level to which an output layer set conforms, wherein a value of 105 indicates a level where a maximum luma sample rate of 4812963840 samples per second is supported; and performing video decoding based on the indicated level.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Provisional Application No.63/084,446, the contents of which are hereby incorporated by referenceinto this application.

TECHNICAL FIELD

This disclosure relates to video coding and more particularly totechniques for signaling profile and level information in video coding.

BACKGROUND

Digital video capabilities can be incorporated into a wide range ofdevices, including digital televisions, laptop or desktop computers,tablet computers, digital recording devices, digital media players,video gaming devices, cellular telephones, including so-calledsmartphones, medical imaging devices, and the like. Digital video may becoded according to a video coding standard. Video coding standardsdefine the format of a compliant bitstream encapsulating coded videodata. A compliant bitstream is a data structure that may be received anddecoded by a video decoding device to generate reconstructed video data.Video coding standards may incorporate video compression techniques.Examples of video coding standards include ISO/IEC MPEG-4 Visual andITU-T H.264 (also known as ISO/IEC MPEG-4 AVC) and High-Efficiency VideoCoding (HEVC). HEVC is described in High Efficiency Video Coding (HEVC),Rec. ITU-T H.265, December 2016, which is incorporated by reference, andreferred to herein as ITU-T H.265. Extensions and improvements for ITU-TH.265 are currently being considered for the development of nextgeneration video coding standards. For example, the ITU-T Video CodingExperts Group (VCEG) and ISO/IEC (Moving Picture Experts Group (MPEG)(collectively referred to as the Joint Video Exploration Team (JVET))are working to standardized video coding technology with a compressioncapability that significantly exceeds that of the current HEVC standard.The Joint Exploration Model 7 (JEM 7), Algorithm Description of JointExploration Test Model 7 (JEM 7), ISO/IEC JTC1/SC29/WG11 Document:JVET-G1001, July 2017, Torino, IT, which is incorporated by referenceherein, describes the coding features that were under coordinated testmodel study by the JVET as potentially enhancing video coding technologybeyond the capabilities of ITU-T H.265. It should be noted that thecoding features of JEM 7 are implemented in JEM reference software. Asused herein, the term JEM may collectively refer to algorithms includedin JEM 7 and implementations of JEM reference software. Further, inresponse to a “Joint Call for Proposals on Video Compression withCapabilities beyond HEVC,” jointly issued by VCEG and MPEG multipledescriptions of video coding tools were proposed by various groups atthe 10^(th) Meeting of ISO/IEC JTC1/SC29/WG11 16-20 Apr. 2018, SanDiego, Calif. From the multiple descriptions of video coding tools, aresulting initial draft text of a video coding specification isdescribed in “Versatile Video Coding (Draft 1),” 10th Meeting of ISO/IECJTC1/SC29/WG11 16-20 Apr. 2018, San Diego, Calif., documentJVET-J1001-v2, which is incorporated by reference herein, and referredto as JVET-J1001. The current development of a next generation videocoding standard by the VCEG and MPEG is referred to as the VersatileVideo Coding (VVC) project. “Versatile Video Coding (Draft 10),” 19thMeeting of ISO/IEC JTC1/SC29/WG11 22 Jun.-1 Jul. 2020, Teleconference,document JVET-52001-vG, which is incorporated by reference herein, andreferred to as JVET-S2001, represents the current iteration of the drafttext of a video coding specification corresponding to the VVC project.

Video compression techniques enable data requirements for storing andtransmitting video data to be reduced. Video compression techniques mayreduce data requirements by exploiting the inherent redundancies in avideo sequence. Video compression techniques may sub-divide a videosequence into successively smaller portions (i.e., groups of pictureswithin a video sequence, a picture within a group of pictures, regionswithin a picture, sub-regions within regions, etc.). Intra predictioncoding techniques (e.g., spatial prediction techniques within a picture)and inter prediction techniques (i.e., inter-picture techniques(temporal)) may be used to generate difference values between a unit ofvideo data to be coded and a reference unit of video data. Thedifference values may be referred to as residual data. Residual data maybe coded as quantized transform coefficients. Syntax elements may relateresidual data and a reference coding unit (e.g., intra-prediction modeindices, and motion information). Residual data and syntax elements maybe entropy coded. Entropy encoded residual data and syntax elements maybe included in data structures forming a compliant bitstream.

SUMMARY

In general, this disclosure describes various techniques for codingvideo data. In particular, this disclosure describes techniques forsignaling profile and level information for coding video data. It shouldbe noted that although techniques of this disclosure are described withrespect to ITU-T H.264, ITU-T H.265, JEM, and JVET-S2001, the techniquesof this disclosure are generally applicable to video coding. Forexample, the coding techniques described herein may be incorporated intovideo coding systems, (including video coding systems based on futurevideo coding standards) including video block structures, intraprediction techniques, inter prediction techniques, transformtechniques, filtering techniques, and/or entropy coding techniques otherthan those included in ITU-T H.265, JEM, and JVET-S2001. Thus, referenceto ITU-T H.264, ITU-T H.265, JEM, and/or JVET-S2001 is for descriptivepurposes and should not be construed to limit the scope of thetechniques described herein. Further, it should be noted thatincorporation by reference of documents herein is for descriptivepurposes and should not be construed to limit or create ambiguity withrespect to terms used herein. For example, in the case where anincorporated reference provides a different definition of a term thananother incorporated reference and/or as the term is used herein, theterm should be interpreted in a manner that broadly includes eachrespective definition and/or in a manner that includes each of theparticular definitions in the alternative.

In one example, a method of decoding video data comprises: receivingprofile tier level syntax; parsing a syntax element, from the profiletier level syntax, indicating a level to which an output layer setconforms, wherein a value of 105 indicates a level where a maximum lumasample rate of 4812963840 samples per second is supported; andperforming video decoding based on the indicated level.

In one example, a device comprises one or more processors configured to:receive profile tier level syntax; parse a syntax element, from theprofile tier level syntax, indicating a level to which an output layerset conforms, wherein a value of 105 indicates a level where a maximumluma sample rate of 4812963840 samples per second is supported; andperform video decoding based on the indicated level.

In one example, a non-transitory computer-readable storage mediumcomprises instructions stored thereon that, when executed, cause one ormore processors of a device to: receive profile tier level syntax; parsea syntax element, from the profile tier level syntax, indicating a levelto which an output layer set conforms, wherein a value of 105 indicatesa level where a maximum luma sample rate of 4812963840 samples persecond is supported; and perform video decoding based on the indicatedlevel.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example of a system that maybe configured to encode and decode video data according to one or moretechniques of this disclosure.

FIG. 2 is a conceptual diagram illustrating coded video data andcorresponding data structures according to one or more techniques ofthis disclosure.

FIG. 3 is a conceptual diagram illustrating a data structureencapsulating coded video data and corresponding metadata according toone or more techniques of this disclosure.

FIG. 4 is a conceptual drawing illustrating an example of componentsthat may be included in an implementation of a system that may beconfigured to encode and decode video data according to one or moretechniques of this disclosure.

FIG. 5 is a block diagram illustrating an example of a video encoderthat may be configured to encode video data according to one or moretechniques of this disclosure.

FIG. 6 is a block diagram illustrating an example of a video decoderthat may be configured to decode video data according to one or moretechniques of this disclosure.

DETAILED DESCRIPTION

Video content includes video sequences comprised of a series of frames(or pictures). A series of frames may also be referred to as a group ofpictures (GOP). Each video frame or picture may be divided into one ormore regions. Regions may be defined according to a base unit (e.g., avideo block) and sets of rules defining a region. For example, a ruledefining a region may be that a region must be an integer number ofvideo blocks arranged in a rectangle. Further, video blocks in a regionmay be ordered according to a scan pattern (e.g., a raster scan). Asused herein, the term video block may generally refer to an area of apicture or may more specifically refer to the largest array of samplevalues that may be predictively coded, sub-divisions thereof, and/orcorresponding structures. Further, the term current video block mayrefer to an area of a picture being encoded or decoded. A video blockmay be defined as an array of sample values. It should be noted that insome cases pixel values may be described as including sample values forrespective components of video data, which may also be referred to ascolor components, (e.g., luma (Y) and chroma (Cb and Cr) components orred, green, and blue components). It should be noted that in some cases,the terms pixel value and sample value are used interchangeably.Further, in some cases, a pixel or sample may be referred to as a pel. Avideo sampling format, which may also be referred to as a chroma format,may define the number of chroma samples included in a video block withrespect to the number of luma samples included in a video block. Forexample, for the 4:2:0 sampling format, the sampling rate for the lumacomponent is twice that of the chroma components for both the horizontaland vertical directions.

A video encoder may perform predictive encoding on video blocks andsub-divisions thereof. Video blocks and sub-divisions thereof may bereferred to as nodes. ITU-T H.264 specifies a macroblock including 16×16luma samples. That is, in ITU-T H.264, a picture is segmented intomacroblocks. ITU-T H.265 specifies an analogous Coding Tree Unit (CTU)structure (which may be referred to as a largest coding unit (LCU)). InITU-T H.265, pictures are segmented into CTUs. In ITU-T H.265, for apicture, a CTU size may be set as including 16×16, 32×32, or 64×64 lumasamples. In ITU-T H.265, a CTU is composed of respective Coding TreeBlocks (CTB) for each component of video data (e.g., luma (Y) and chroma(Cb and Cr). It should be noted that video having one luma component andthe two corresponding chroma components may be described as having twochannels, i.e., a luma channel and a chroma channel. Further, in ITU-TH.265, a CTU may be partitioned according to a quadtree (QT)partitioning structure, which results in the CTBs of the CTU beingpartitioned into Coding Blocks (CB). That is, in ITU-T H.265, a CTU maybe partitioned into quadtree leaf nodes. According to ITU-T H.265, oneluma CB together with two corresponding chroma CBs and associated syntaxelements are referred to as a coding unit (CU). In ITU-T H.265, aminimum allowed size of a CB may be signaled. In ITU-T H.265, thesmallest minimum allowed size of a luma CB is 8×8 luma samples. In ITU-TH.265, the decision to code a picture area using intra prediction orinter prediction is made at the CU level.

In ITU-T H.265, a CU is associated with a prediction unit structurehaving its root at the CU. In ITU-T H.265, prediction unit structuresallow luma and chroma CBs to be split for purposes of generatingcorresponding reference samples. That is, in ITU-T H.265, luma andchroma CBs may be split into respective luma and chroma predictionblocks (PBs), where a PB includes a block of sample values for which thesame prediction is applied. In ITU-T H.265, a CB may be partitioned into1, 2, or 4 PBs. ITU-T H.265 supports PB sizes from 64×64 samples down to4×4 samples. In ITU-T H.265, square PBs are supported for intraprediction, where a CB may form the PB or the CB may be split into foursquare PBs. In ITU-T H.265, in addition to the square PBs, rectangularPBs are supported for inter prediction, where a CB may be halvedvertically or horizontally to form PBs. Further, it should be noted thatin ITU-T H.265, for inter prediction, four asymmetric PB partitions aresupported, where the CB is partitioned into two PBs at one quarter ofthe height (at the top or the bottom) or width (at the left or theright) of the CB. Intra prediction data (e.g., intra prediction modesyntax elements) or inter prediction data (e.g., motion data syntaxelements) corresponding to a PB is used to produce reference and/orpredicted sample values for the PB.

JEM specifies a CTU having a maximum size of 256×256 luma samples. JEMspecifies a quadtree plus binary tree (QTBT) block structure. In JEM,the QTBT structure enables quadtree leaf nodes to be further partitionedby a binary tree (BT) structure. That is, in JEM, the binary treestructure enables quadtree leaf nodes to be recursively dividedvertically or horizontally. In JVET-S2001, CTUs are partitionedaccording a quadtree plus multi-type tree (QTMT or QT+MTT) structure.The QTMT in JVET-S2001 is similar to the QTBT in JEM. However, inJVET-S2001, in addition to indicating binary splits, the multi-type treemay indicate so-called ternary (or triple tree (TT)) splits. A ternarysplit divides a block vertically or horizontally into three blocks. Inthe case of a vertical TT split, a block is divided at one quarter ofits width from the left edge and at one quarter its width from the rightedge and in the case of a horizontal TT split a block is at one quarterof its height from the top edge and at one quarter of its height fromthe bottom edge.

As described above, each video frame or picture may be divided into oneor more regions. For example, according to ITU-T H.265, each video frameor picture may be partitioned to include one or more slices and furtherpartitioned to include one or more tiles, where each slice includes asequence of CTUs (e.g., in raster scan order) and where a tile is asequence of CTUs corresponding to a rectangular area of a picture. Itshould be noted that a slice, in ITU-T H.265, is a sequence of one ormore slice segments starting with an independent slice segment andcontaining all subsequent dependent slice segments (if any) that precedethe next independent slice segment (if any). A slice segment, like aslice, is a sequence of CTUs. Thus, in some cases, the terms slice andslice segment may be used interchangeably to indicate a sequence of CTUsarranged in a raster scan order. Further, it should be noted that inITU-T H.265, a tile may consist of CTUs contained in more than one sliceand a slice may consist of CTUs contained in more than one tile.However, ITU-T H.265 provides that one or both of the followingconditions shall be fulfilled: (1) All CTUs in a slice belong to thesame tile; and (2) All CTUs in a tile belong to the same slice.

With respect to JVET-S2001, slices are required to consist of an integernumber of complete tiles or an integer number of consecutive completeCTU rows within a tile, instead of only being required to consist of aninteger number of CTUs. It should be noted that in JVET-S2001, the slicedesign does not include slice segments (i.e., no independent/dependentslice segments). Thus, in JVET-S2001, a picture may include a singletile, where the single tile is contained within a single slice or apicture may include multiple tiles where the multiple tiles (or CTU rowsthereof) may be contained within one or more slices. In JVET-S2001, thepartitioning of a picture into tiles is specified by specifyingrespective heights for tile rows and respective widths for tile columns.Thus, in JVET-S2001 a tile is a rectangular region of CTUs within aparticular tile row and a particular tile column position. Further, itshould be noted that JVET-S2001 provides where a picture may bepartitioned into subpictures, where a subpicture is a rectangular regionof a CTUs within a picture. The top-left CTU of a subpicture may belocated at any CTU position within a picture with subpictures beingconstrained to include one or more slices Thus, unlike a tile, asubpicture is not necessarily limited to a particular row and columnposition. It should be noted that subpictures may be useful forencapsulating regions of interest within a picture and a sub-bitstreamextraction process may be used to only decode and display a particularregion of interest. That is, as described in further detail below, abitstream of coded video data includes a sequence of network abstractionlayer (NAL) units, where a NAL unit encapsulates coded video data,(i.e., video data corresponding to a slice of picture) or a NAL unitencapsulates metadata used for decoding video data (e.g., a parameterset) and a sub-bitstream extraction process forms a new bitstream byremoving one or more NAL units from a bitstream.

FIG. 2 is a conceptual diagram illustrating an example of a picturewithin a group of pictures partitioned according to tiles, slices, andsubpictures. It should be noted that the techniques described herein maybe applicable to tiles, slices, subpictures, sub-divisions thereofand/or equivalent structures thereto. That is, the techniques describedherein may be generally applicable regardless of how a picture ispartitioned into regions. For example, in some cases, the techniquesdescribed herein may be applicable in cases where a tile may bepartitioned into so-called bricks, where a brick is a rectangular regionof CTU rows within a particular tile. Further, for example, in somecases, the techniques described herein may be applicable in cases whereone or more tiles may be included in so-called tile groups, where a tilegroup includes an integer number of adjacent tiles. In the exampleillustrated in FIG. 2, Pic₃ is illustrated as including 16 tiles (i.e.,Tile₀ to Tile₁₅) and three slices (i.e., Slice₀ to Slice₂). In theexample illustrated in FIG. 2, Slice₀ includes four tiles (i.e., Tile₀to Tile₃), Slice₁ includes eight tiles (i.e., Tile₄ to Tile₁₁), andSlice₂ includes four tiles (i.e., Tile₁₂ to Tile₁₅). Further, asillustrated in the example of FIG. 2, Pic₃ is illustrated as includingtwo subpictures (i.e., Subpicture₀ and Subpicture₁), where Subpicture₀includes Slice₀ and Slice₁ and where Subpicture₁ includes Slice₂. Asdescribed above, subpictures may be useful for encapsulating regions ofinterest within a picture and a sub-bitstream extraction process may beused in order to selectively decode (and display) a region interest. Forexample, referring to FIG. 2, Subpicture₀ may corresponding to an actionportion of a sporting event presentation (e.g., a view of the field) andSubpicture₁ may corresponding to a scrolling banner displayed during thesporting event presentation. By using organizing a picture intosubpictures in this manner, a viewer may be able to disable the displayof the scrolling banner. That is, through a sub-bitstream extractionprocess Slice₂ NAL unit may be removed from a bitstream (and thus notdecoded and/or displayed) and Slice₀ NAL unit and Slice₁ NAL unit may bedecoded and displayed. The encapsulation of slices of a picture intorespective NAL unit data structures and sub-bitstream extraction aredescribed in further detail below.

For intra prediction coding, an intra prediction mode may specify thelocation of reference samples within a picture. In ITU-T H.265, definedpossible intra prediction modes include a planar (i.e., surface fitting)prediction mode, a DC (i.e., flat overall averaging) prediction mode,and 33 angular prediction modes (predMode: 2-34). In JEM, definedpossible intra-prediction modes include a planar prediction mode, a DCprediction mode, and 65 angular prediction modes. It should be notedthat planar and DC prediction modes may be referred to asnon-directional prediction modes and that angular prediction modes maybe referred to as directional prediction modes. It should be noted thatthe techniques described herein may be generally applicable regardlessof the number of defined possible prediction modes.

For inter prediction coding, a reference picture is determined and amotion vector (MV) identifies samples in the reference picture that areused to generate a prediction for a current video block. For example, acurrent video block may be predicted using reference sample valueslocated in one or more previously coded picture(s) and a motion vectoris used to indicate the location of the reference block relative to thecurrent video block. A motion vector may describe, for example, ahorizontal displacement component of the motion vector (i.e., MV_(x)), avertical displacement component of the motion vector (i.e., MV_(y)), anda resolution for the motion vector (e.g., one-quarter pixel precision,one-half pixel precision, one-pixel precision, two-pixel precision,four-pixel precision). Previously decoded pictures, which may includepictures output before or after a current picture, may be organized intoone or more to reference pictures lists and identified using a referencepicture index value. Further, in inter prediction coding, uni-predictionrefers to generating a prediction using sample values from a singlereference picture and bi-prediction refers to generating a predictionusing respective sample values from two reference pictures. That is, inuni-prediction, a single reference picture and corresponding motionvector are used to generate a prediction for a current video block andin bi-prediction, a first reference picture and corresponding firstmotion vector and a second reference picture and corresponding secondmotion vector are used to generate a prediction for a current videoblock. In bi-prediction, respective sample values are combined (e.g.,added, rounded, and clipped, or averaged according to weights) togenerate a prediction. Pictures and regions thereof may be classifiedbased on which types of prediction modes may be utilized for encodingvideo blocks thereof. That is, for regions having a B type (e.g., a Bslice), bi-prediction, uni-prediction, and intra prediction modes may beutilized, for regions having a P type (e.g., a P slice), uni-prediction,and intra prediction modes may be utilized, and for regions having an Itype (e.g., an I slice), only intra prediction modes may be utilized. Asdescribed above, reference pictures are identified through referenceindices. For example, for a P slice, there may be a single referencepicture list, RefPicList0 and for a B slice, there may be a secondindependent reference picture list, RefPicList1, in addition toRefPicList0. It should be noted that for uni-prediction in a B slice,one of RefPicList0 or RefPicList1 may be used to generate a prediction.Further, it should be noted that during the decoding process, at theonset of decoding a picture, reference picture list(s) are generatedfrom previously decoded pictures stored in a decoded picture buffer(DPB).

Further, a coding standard may support various modes of motion vectorprediction. Motion vector prediction enables the value of a motionvector for a current video block to be derived based on another motionvector. For example, a set of candidate blocks having associated motioninformation may be derived from spatial neighboring blocks and temporalneighboring blocks to the current video block. Further, generated (ordefault) motion information may be used for motion vector prediction.Examples of motion vector prediction include advanced motion vectorprediction (AMVP), temporal motion vector prediction (TMVP), so-called“merge” mode, and “skip” and “direct” motion inference. Further, otherexamples of motion vector prediction include advanced temporal motionvector prediction (ATMVP) and Spatial-temporal motion vector prediction(STMVP). For motion vector prediction, both a video encoder and videodecoder perform the same process to derive a set of candidates. Thus,for a current video block, the same set of candidates is generatedduring encoding and decoding.

As described above, for inter prediction coding, reference samples in apreviously coded picture are used for coding video blocks in a currentpicture. Previously coded pictures which are available for use asreference when coding a current picture are referred as referencepictures. It should be noted that the decoding order does not necessarycorrespond with the picture output order, i.e., the temporal order ofpictures in a video sequence. In ITU-T H.265, when a picture is decodedit is stored to a decoded picture buffer (DPB) (which may be referred toas frame buffer, a reference buffer, a reference picture buffer, or thelike). In ITU-T H.265, pictures stored to the DPB are removed from theDPB when they been output and are no longer needed for coding subsequentpictures. In ITU-T H.265, a determination of whether pictures should beremoved from the DPB is invoked once per picture, after decoding a sliceheader, i.e., at the onset of decoding a picture. For example, referringto FIG. 2, Pic₂ is illustrated as referencing Pic₁. Similarly, Pic₃ isillustrated as referencing Pic₀. With respect to FIG. 2, assuming thepicture number corresponds to the decoding order, the DPB would bepopulated as follows: after decoding Pic₀, the DPB would include {Pic₀};at the onset of decoding Pic_(k), the DPB would include {Pic₀}; afterdecoding Pic_(k), the DPB would include {Pic₀, Pic_(k)}; at the onset ofdecoding Pic₂, the DPB would include {Pic₀, Pic_(k)}. Pic₂ would then bedecoded with reference to Pic_(k) and after decoding Pic₂, the DPB wouldinclude {Pic₀, Pic_(k), Pic₂}. At the onset of decoding Pic₃, picturesPic₀ and Pic_(k) would be marked for removal from the DPB, as they arenot needed for decoding Pic₃ (or any subsequent pictures, not shown) andassuming Pic_(k) and Pic₂ have been output, the DPB would be updated toinclude {Pic₀}. Pic₃ would then be decoded by referencing Pic₀. Theprocess of marking pictures for removal from a DPB may be referred to asreference picture set (RPS) management.

As described above, intra prediction data or inter prediction data isused to produce reference sample values for a block of sample values.The difference between sample values included in a current PB, oranother type of picture area structure, and associated reference samples(e.g., those generated using a prediction) may be referred to asresidual data. Residual data may include respective arrays of differencevalues corresponding to each component of video data. Residual data maybe in the pixel domain. A transform, such as, a discrete cosinetransform (DCT), a discrete sine transform (DST), an integer transform,a wavelet transform, or a conceptually similar transform, may be appliedto an array of difference values to generate transform coefficients. Itshould be noted that in ITU-T H.265 and JVET-S2001, a CU is associatedwith a transform tree structure having its root at the CU level. Thetransform tree is partitioned into one or more transform units (TUs).That is, an array of difference values may be partitioned for purposesof generating transform coefficients (e.g., four 8×8 transforms may beapplied to a 16×16 array of residual values). For each component ofvideo data, such sub-divisions of difference values may be referred toas Transform Blocks (TBs). It should be noted that in some cases, a coretransform and subsequent secondary transforms may be applied (in thevideo encoder) to generate transform coefficients. For a video decoder,the order of transforms is reversed.

A quantization process may be performed on transform coefficients orresidual sample values directly (e.g., in the case, of palette codingquantization). Quantization approximates transform coefficients byamplitudes restricted to a set of specified values. Quantizationessentially scales transform coefficients in order to vary the amount ofdata required to represent a group of transform coefficients.Quantization may include division of transform coefficients (or valuesresulting from the addition of an offset value to transformcoefficients) by a quantization scaling factor and any associatedrounding functions (e.g., rounding to the nearest integer). Quantizedtransform coefficients may be referred to as coefficient level values.Inverse quantization (or “dequantization”) may include multiplication ofcoefficient level values by the quantization scaling factor, and anyreciprocal rounding or offset addition operations. It should be notedthat as used herein the term quantization process in some instances mayrefer to division by a scaling factor to generate level values andmultiplication by a scaling factor to recover transform coefficients insome instances. That is, a quantization process may refer toquantization in some cases and inverse quantization in some cases.Further, it should be noted that although in some of the examples belowquantization processes are described with respect to arithmeticoperations associated with decimal notation, such descriptions are forillustrative purposes and should not be construed as limiting. Forexample, the techniques described herein may be implemented in a deviceusing binary operations and the like. For example, multiplication anddivision operations described herein may be implemented using bitshifting operations and the like.

Quantized transform coefficients and syntax elements (e.g., syntaxelements indicating a coding structure for a video block) may be entropycoded according to an entropy coding technique. An entropy codingprocess includes coding values of syntax elements using lossless datacompression algorithms. Examples of entropy coding techniques includecontent adaptive variable length coding (CAVLC), context adaptive binaryarithmetic coding (CABAC), probability interval partitioning entropycoding (PIPE), and the like. Entropy encoded quantized transformcoefficients and corresponding entropy encoded syntax elements may forma compliant bitstream that can be used to reproduce video data at avideo decoder. An entropy coding process, for example, CABAC, mayinclude performing a binarization on syntax elements. Binarizationrefers to the process of converting a value of a syntax element into aseries of one or more bits. These bits may be referred to as “bins.”Binarization may include one or a combination of the following codingtechniques: fixed length coding, unary coding, truncated unary coding,truncated Rice coding, Golomb coding, k-th order exponential Golombcoding, and Golomb-Rice coding. For example, binarization may includerepresenting the integer value of 5 for a syntax element as 00000101using an 8-bit fixed length binarization technique or representing theinteger value of 5 as 11110 using a unary coding binarization technique.As used herein each of the terms fixed length coding, unary coding,truncated unary coding, truncated Rice coding, Golomb coding, k-th orderexponential Golomb coding, and Golomb-Rice coding may refer to generalimplementations of these techniques and/or more specific implementationsof these coding techniques. For example, a Golomb-Rice codingimplementation may be specifically defined according to a video codingstandard. In the example of CABAC, for a particular bin, a contextprovides a most probable state (MPS) value for the bin (i.e., an MPS fora bin is one of 0 or 1) and a probability value of the bin being the MPSor the least probably state (LPS). For example, a context may indicate,that the MPS of a bin is 0 and the probability of the bin being 1 is0.3. It should be noted that a context may be determined based on valuesof previously coded bins including bins in the current syntax elementand previously coded syntax elements. For example, values of syntaxelements associated with neighboring video blocks may be used todetermine a context for a current bin.

With respect to the equations used herein, the following arithmeticoperators may be used:

-   -   + Addition    -   − Subtraction

-   * Multiplication, including matrix multiplication    -   x^(y) Exponentiation. Specifies x to the power of y. In other        contexts, such notation is used for superscripting not intended        for interpretation as exponentiation.    -   / Integer division with truncation of the result toward zero.        For example, 7/4 and −7/−4 are truncated to 1 and −7/4 and 7/−4        are truncated to −1.    -   ÷ Used to denote division in mathematical equations where no        truncation or rounding is intended.

$\frac{x}{y}$

Used to denote division in mathematical equations where no truncation orrounding is intended.

Further, the following mathematical functions may be used:

-   -   Log 2(x) the base-2 logarithm of x;

${{Min}( {x,y} )} = \{ {\begin{matrix}x & ; & {x<=y} \\y & ; & {x > y}\end{matrix};{{{Max}( {x,y} )} = \{ \begin{matrix}x & ; & {x>=y} \\y & ; & {x < y}\end{matrix} }} $

-   -   Ceil(x) the smallest integer greater than or equal to x.    -   Sqrt(x) square root of x

With respect to the example syntax used herein, the followingdefinitions of logical operators may be applied:

-   -   x && y Boolean logical “and” of x and y    -   x∥y Boolean logical “or” of x and y    -   !Boolean logical “not”    -   x?y:z If x is TRUE or not equal to 0, evaluates to the value of        y; otherwise, evaluates to the value of z.

Further, the following relational operators may be applied:

-   -   > Greater than    -   >= Greater than or equal to    -   < Less than    -   <= Less than or equal to    -   == Equal to    -   != Not equal to

Further, it should be noted that in the syntax descriptors used herein,the following descriptors may be applied:

-   -   b(8): byte having any pattern of bit string (8 bits). The        parsing process for this descriptor is specified by the return        value of the function read_bits(8).    -   f(n): fixed-pattern bit string using n bits written (from left        to right) with the left bit first. The parsing process for this        descriptor is specified by the return value of the function        read_bits(n).    -   se(v): signed integer 0-th order Exp-Golomb-coded syntax element        with the left bit first.    -   tb(v): truncated binary using up to maxVal bits with maxVal        defined in the semantics of the symtax element.    -   tu(v): truncated unary using up to maxVal bits with maxVal        defined in the semantics of the symtax element.    -   u(n): unsigned integer using n bits. When n is “v” in the syntax        table, the number of bits varies in a manner dependent on the        value of other syntax elements. The parsing process for this        descriptor is specified by the return value of the function        read_bits(n) interpreted as a binary representation of an        unsigned integer with most significant bit written first.    -   ue(v): unsigned integer 0-th order Exp-Golomb-coded syntax        element with the left bit first.

As described above, video content includes video sequences comprised ofa series of pictures and each picture may be divided into one or moreregions. In JVET-S2001, a coded representation of a picture comprisesvideo coding layer (VCL) NAL units of a particular layer within an AUand contains all CTUs of the picture. For example, referring again toFIG. 2, the coded representation of Pica is encapsulated in three codedslice NAL units (i.e., Slice₀ NAL unit, Slices NAL unit, and Slice₂ NALunit). It should be noted that the term video coding layer (VCL) NALunit is used as a collective term for coded slice NAL units, i.e., VCLNAL is a collective term which includes all types of slice NAL units. Asdescribed above, and in further detail below, a NAL unit may encapsulatemetadata used for decoding video data. A NAL unit encapsulating metadataused for decoding a video sequence is generally referred to as a non-VCLNAL unit. Thus, in JVET-S2001, a NAL unit may be a VCL NAL unit or anon-VCL NAL unit. It should be noted that a VCL NAL unit includes sliceheader data, which provides information used for decoding the particularslice. Thus, in JVET-S2001, information used for decoding video data,which may be referred to as metadata in some cases, is not limited tobeing included in non-VCL NAL units. JVET-S2001 provides where a pictureunit (PU) is a set of NAL units that are associated with each otheraccording to a specified classification rule, are consecutive indecoding order, and contain exactly one coded picture and where anaccess unit (AU) is a set of PUs that belong to different layers andcontain coded pictures associated with the same time for output from theDPB. JVET-S2001 further provides where a layer is a set of VCL NAL unitsthat all have a particular value of a layer identifier and theassociated non-VCL NAL units. Further, in JVET-S2001, a PU consists ofzero or one PH NAL units, one coded picture, which comprises of one ormore VCL NAL units, and zero or more other non-VCL NAL units. Further,in JVET-S2001, a coded video sequence (CVS) is a sequence of AUs thatconsists, in decoding order, of a CVSS AU, followed by zero or more AUsthat are not CVSS AUs, including all subsequent AUs up to but notincluding any subsequent AU that is a CVSS AU, where a coded videosequence start (CVSS) AU is an AU in which there is a PU for each layerin the CVS and the coded picture in each present picture unit is a codedlayer video sequence start (CLVSS) picture. In JVET-S2001, a coded layervideo sequence (CLVS) is a sequence of PUs within the same layer thatconsists, in decoding order, of a CLVSS PU, followed by zero or more PUsthat are not CLVSS PUs, including all subsequent PUs up to but notincluding any subsequent PU that is a CLVSS PU. This is, in JVET-S2001,a bitstream may be described as including a sequence of AUs forming oneor more CVSs.

Multi-layer video coding enables a video presentation to bedecoded/displayed as a presentation corresponding to a base layer ofvideo data and decoded/displayed as one or more additional presentationscorresponding to enhancement layers of video data. For example, a baselayer may enable a video presentation having a basic level of quality(e.g., a High Definition rendering and/or a 30 Hz frame rate) to bepresented and an enhancement layer, together with a base layer, mayenable a video presentation having an enhanced level of quality (e.g.,an Ultra High Definition rendering and/or a 60 Hz frame rate) to bepresented. It should be noted that there are various ways to specifyframe rate, e.g., Hz or frames per second (fps). An enhancement layermay be coded by referencing a base layer. That is, for example, apicture in an enhancement layer may be coded (e.g., using inter-layerprediction techniques) by referencing one or more pictures (includingscaled versions thereof) in a base layer. It should be noted that layersmay also be coded independent of each other. In this case, there may notbe inter-layer prediction between two layers. Each NAL unit may includean identifier indicating a layer of video data the NAL unit isassociated with. As described above, a sub-bitstream extraction processmay be used to only decode and display a particular region of interestof a picture. Further, a sub-bitstream extraction process may be used toonly decode and display a particular layer of video. Further, asub-bitstream extraction process may be used to only decode and displaya particular sublayer of video. Sub-bitstream extraction may refer to aprocess where a device receiving a compliant or conforming bitstreamforms a new compliant or conforming bitstream by discarding and/ormodifying data in the received bitstream. For example, sub-bitstreamextraction may be used to form a new compliant or conforming bitstreamcorresponding to a particular representation of video (e.g., a highquality representation).

In JVET-S2001, each of a video sequence, a GOP, a picture, a slice, andCTU may be associated with metadata that describes video codingproperties and some types of metadata encapsulated in non-VCL NAL units.JVET-S2001 defines parameters sets that may be used to describe videodata and/or video coding properties. In particular, JVET-S2001 includesthe following four types of parameter sets: video parameter set (VPS),sequence parameter set (SPS), picture parameter set (PPS), and adaptionparameter set (APS), where a SPS applies to zero or more entire CLVSs, aPPS applies to zero or more entire coded pictures, a APS applies to zeroor more slices, and a VPS may be optionally referenced by a SPS. A PPSapplies to an individual coded picture that refers to it. In JVET-S2001,parameter sets may be encapsulated as a non-VCL NAL unit and/or may besignaled as a message. JVET-S2001 also includes a picture header (PH)which is encapsulated as a non-VCL NAL unit. In JVET-S2001, a pictureheader applies to all slices of a coded picture. JVET-S2001 furtherenables decoding capability information (DCI) and supplementalenhancement information (SEI) messages to be signaled. In JVET-S2001,DCI and SEI messages assist in processes related to decoding, display orother purposes, however, DCI and SEI messages may not be required forconstructing the luma or chroma samples according to a decoding process.In JVET-S2001, DCI and SEI messages may be signaled in a bitstream usingnon-VCL NAL units. Further, DCI and SEI messages and other non-VCL NALunits, including parameter sets may be conveyed by some mechanism otherthan by being present in the bitstream (i.e., signaled out-of-band).

FIG. 3 illustrates an example of a bitstream including multiple CVSs,where a CVS includes AUs, and AUs include picture units. The exampleillustrated in FIG. 3 corresponds to an example of encapsulating theslice NAL units illustrated in the example of FIG. 2 in a bitstream. Inthe example illustrated in FIG. 3, the corresponding picture unit forPic₃ includes the three VCL NAL coded slice NAL units, i.e., Slice₀ NALunit, Slice₁ NAL unit, and Slice₂ NAL unit and two non-VCL NAL units,i.e., a PPS NAL Unit and a PH NAL unit. It should be noted that in FIG.3, HEADER is a NAL unit header (i.e., not to be confused with a sliceheader). Further, it should be noted that in FIG. 3, other non-VCL NALunits, which are not illustrated may be included in the CVSs, e.g., SPSNAL units, VPS NAL units, SEI message NAL units, etc. Further, it shouldbe noted that in other examples, a PPS NAL Unit used for decoding Pic₃may be included elsewhere in the bitstream, e.g., in the picture unitcorresponding to Pic₀ or may be provided by an external mechanism. Asdescribed in further detail below, in JVET-S2001, a PH syntax structuremay be present in the slice header of a VCL NAL unit or in a PH NAL unitof the current PU.

As described above, multi-layer video coding enables a videopresentation corresponding to a base layer of video data and one or moreadditional presentations corresponding to enhancement layers of videodata. With respect to multi-layer video, it should be noted thatJVET-S2001 provides the following definitions:

-   access unit (AU): A set of PUs that belong to different layers and    contain coded pictures associated with the same time for output from    the DPB.-   coded picture: A coded representation of a picture comprising VCL    NAL units with a particular value of nuh_layer_id within an AU and    containing all CTUs of the picture.-   layer: A set of VCL NAL units that all have a particular value of    nuh_layer_id and the associated non-VCL NAL units.-   level: A defined set of constraints on the values that may be taken    by the syntax elements and variables of JVET-S2001, or the value of    a transform coefficient prior to scaling.    -   NOTE—The same set of levels is defined for all profiles, with        most aspects of the definition of each level being in common        across different profiles. Individual implementations could,        within the specified constraints, support a different level for        each supported profile.-   operation point (OP): A temporal subset of an OLS, identified by an    OLS index and a highest value of TemporalId.-   output layer: A layer of an output layer set that is output.-   output layer set (OLS): A set of layers for which one or more layers    are specified as the output layers.-   output layer set (OLS) layer index: An index, of a layer in an OLS,    to the list of layers in the OLS.-   picture unit (PU): A set of NAL units that are associated with each    other according to a specified classification rule, are consecutive    in decoding order, and contain exactly one coded picture.-   profile: A specified subset of the syntax of JVET-S2001.-   sublayer: A temporal scalable layer of a temporal scalable    bitstream, consisting of VCL NAL units with a particular value of    the TemporalId variable and the associated non-VCL NAL units.-   sublayer representation: A subset of the bitstream consisting of NAL    units of a particular sublayer and the lower sublayers.-   tier: A specified category of level constraints imposed on values of    the syntax elements in the bitstream, where the level constraints    are nested within a tier and a decoder conforming to a certain tier    and level would be capable of decoding all bitstreams that conform    to the same tier or the lower tier of that level or any level below    it.

Thus, according to JVET-S2001, profiles, tiers and levels specifyrestrictions on bitstreams and hence limits on the capabilities neededto decode the bitstreams. Profiles, tiers and levels are also used toindicate the capability of individual decoder implementations andinteroperability points between encoders and decoders. That is, eachoperating point will conform to a profile, tier, and level. Further,according to JVET-S2001, an operation point, which may be referred to asan operating point, is a particular temporal subset of an output layerset, where output layer set is a set of layers for which one or morelayers are specified as output layers. A temporal subset contains one ormore temporal sublayers. For example, a layer in JVET-S2001 may includetwo temporal sub-layers. The lowest temporal sub-layer 0, results in a30 Hz frame rate or picture rate video. Both the temporal sublayerstogether result in 60 Hz frame rate or picture rate video. Thus, thelayer may include two operation points, (1) an operation point where thehighest temporal sublayer which is decoded is temporal sublayer 0, the30 Hz video sublayer and (2) an operation point where the highesttemporal sublayer which is decoded is temporal sublayer 1, which alongwith temporal sublayer 0 which is also decoded results in the 60 Hzvideo (which includes decoding the 30 Hz sublayer-temporal sublayer 0).

In another example, a bitstream may include two layers, layer 0 andlayer 1, where each layer includes two temporal sublayers, sublayer 0and sublayer 1. Further, in this case, layer 1 may be encoded usinglayer 0 as a reference layer. In this case, there may be followingoperation points or operating points defined:

-   -   An operation point which includes only sublayer 0 of layer 0    -   An operation point which includes only sublayer 0 and sublayer 1        of layer 0    -   An operation point which includes only sublayer 0 of layer 0,        and sublayer 0 of layer 1    -   An operation point which includes only sublayer 0 and sublayer 1        of layer 0, and sublayer 0 and sublayer 1 of layer 1

With respect to nuh_layer_id and TemporalId in the definitions above,JVET-S2001 defines NAL unit header semantics that specify the type ofRaw Byte Sequence Payload (RBSP) data structure included in the NALunit. Table 1 illustrates the syntax of the NAL unit header provided inJVET-S2001.

TABLE 1 Descriptor nal_unit_header( ) {  forbidden_zero_bit f(1) nuh_reserved_zero_bit u(1)  nuh_layer_id u(6)  nal_unit_type u(5) nuh_temporal_id_plus1 u(3) }

JVET-S2001 provides the following definitions for the respective syntaxelements illustrated in Table 1.

-   forbidden_zero_bit shall be equal to 0.-   nuh_reserved_zero_bit shall be equal to 0. The value 1 of    nuh_reserved_zero_bit could be specified in the future by ITU    T|ISO/IEC. Although the value of nuh_reserved_zero_bit is required    to be equal to 0 in this version of this Specification, decoders    conforming to this version of this Specification shall allow the    value of nuh_reserved_zero_bit equal to 1 to appear in the syntax    and shall ignore (i.e. remove from the bitstream and discard) NAL    units with nuh_reserved_zero_bit equal to 1.-   nuh_layer_id specifies the identifier of the layer to which a VCL    NAL unit belongs or the identifier of a layer to which a non-VCL NAL    unit applies. The value of nuh_layer_id shall be in the range of 0    to 55, inclusive. Other values for nuh_layer_id are reserved for    future use by ITU-T|ISO/IEC. Although the value of nuh_layer_id is    required to be the range of 0 to 55, inclusive, in this version of    this Specification, decoders conforming to this version of this    Specification shall allow the value of nuh_layer_id to be greater    than 55 to appear in the syntax and shall ignore (i.e. remove from    the bitstream and discard) NAL units with nuh_layer_id greater than    55.

The value of nuh_layer_id shall be the same for all VCL NAL units of acoded picture. The value of nuh_layer_id of a coded picture or a PU isthe value of the nuh_layer_id of the VCL NAL units of the coded pictureor the PU.

When nal_unit_type is equal to PH_NUT, or FD_NUT, nuh_layer_id shall beequal to the nuh_layer_id of associated VCL NAL unit.

When nal_unit_type is equal to EOS_NUT, nuh_layer_id shall be equal toone of the nuh_layer_id values of the layers present in the CVS.

NOTE—The value of nuh_layer_id for DCI, OPI, VPS, AUD, and EOB NAL unitsis not constrained.

-   nuh_temporal_id_plus1 minus 1 specifies a temporal identifier for    the NAL unit.

The value of nuh_temporal_id_plus1 shall not be equal to 0.

The variable TemporalId is derived as follows:

-   -   TemporalId=nuh_temporal_id_plus1−1

When nal_unit_type is in the range of IDR_W_RADL to RSV_IRAP_11,inclusive, TemporalId shall be equal to 0. When nal_unit_type is equalto STSA_NUT andvps_independent_layer_flag[GeneralLayerIdx[nuh_layer_id]] is equal to 1,TemporalId shall be greater than 0.

The value of TemporalId shall be the same for all VCL NAL units of anAU. The value of TemporalId of a coded picture, a PU, or an AU is thevalue of the TemporalId of the VCL NAL units of the coded picture, PU,or AU. The value of TemporalId of a sublayer representation is thegreatest value of TemporalId of all VCL NAL units in the sublayerrepresentation.

The value of TemporalId for non-VCL NAL units is constrained as follows:

-   -   If nal_unit_type is equal to DCI_NUT, OPI_NUT, VPS_NUT, or        SPS_NUT, TemporalId shall be equal to 0 and the TemporalId of        the AU containing the NAL unit shall be equal to 0.    -   Otherwise, if nal_unit_type is equal to PH_NUT, TemporalId shall        be equal to the TemporalId of the PU containing the NAL unit.    -   Otherwise, if nal_unit_type is equal to EOS_NUT or EOB_NUT,        TemporalId shall be equal to 0.    -   Otherwise, if nal_unit_type is equal to AUD_NUT, FD_NUT,        PREFIX_SEI_NUT, or SUFFIX_SEI_NUT, TemporalId shall be equal to        the TemporalId of the AU containing the NAL unit.    -   Otherwise, when nal_unit_type is equal to PPS_NUT,        PREFIX_APS_NUT, or SUFFIX_APS_NUT, TemporalId shall be greater        than or equal to the TemporalId of the PU containing the NAL        unit.

NOTE—When the NAL unit is a non-VCL NAL unit, the value of TemporalId isequal to the minimum value of the TemporalId values of all AUs to whichthe non-VCL NAL unit applies. When nal_unit_type is equal to PPS_NUT,PREFIX_APS_NUT, or SUFFIX_APS_NUT, TemporalId could be greater than orequal to the TemporalId of the containing AU, as all PPSs and APSs couldbe included in the beginning of the bitstream (e.g., when they aretransported out-of-band, and the receiver places them at the beginningof the bitstream), wherein the first coded picture has TemporalId equalto 0.

-   nal_unit_type specifies the NAL unit type, i.e., the type of RBSP    data structure contained in the NAL unit as specified in Table 2.

NAL units that have nal_unit_type in the range of UNSPEC_28 . . .UNSPEC_31, inclusive, for which semantics are not specified, shall notaffect the decoding process specified in this Specification.

NOTE—NAL unit types in the range of UNSPEC_28 . . . UNSPEC_31 could beused as determined by the application. No decoding process for thesevalues of nal_unit_type is specified in this Specification. Sincedifferent applications might use these NAL unit types for differentpurposes, particular care is expected to be exercised in the design ofencoders that generate NAL units with these nal_unit_type values, and inthe design of decoders that interpret the content of NAL units withthese nal_unit_type values. This Specification does not define anymanagement for these values. These nal_unit_type values might only besuitable for use in contexts in which “collisions” of usage (i.e.,different definitions of the meaning of the NAL unit content for thesame nal_unit_type value) are unimportant, or not possible, or aremanaged—e.g., defined or managed in the controlling application ortransport specification, or by controlling the environment in whichbitstreams are distributed.

For purposes other than determining the amount of data in the DUs of thebitstream (as specified in Annex C), decoders shall ignore (remove fromthe bitstream and discard) the contents of all NAL units that usereserved values of nal_unit_type.

NOTE—This requirement allows future definition of compatible extensionsto this Specification.

TABLE 2 Name of NAL unit nal_unit_type nal_unit_type Content of NAL unitand RBSP syntax structure type class  0 TRAIL_NUT Coded slice of atrailing picture or subpicture* VCL slice_layer_rbsp( )  1 STSA_NUTCoded slice of an STSA picture or subpicture* VCL slice_layer_rbsp( ) 2RADL_NUT Coded slice of a RADL picture or subpicture* VCLslice_layer_rbsp( )  3 RASL_NUT Coded slice of a RASL picture orsubpicture* VCL slice_layer_rbsp( ) 4 . . . 6 RSV_VCL_4 . . . Reservednon-IRAP VCL NAL unit types VCL RSV_VCL_6  7 IDR_W_RADL Coded slice ofan IDR picture or subpicture* VCL  8 IDR_N_LP slice_layer_rbsp( )  9CRA_NUT Coded slice of a CRA picture or subpicture* VCLslice_layer_rbsp( ) 10 GDR_NUT Coded slice of a GDR picture orsubpicture* VCL slice_layer_rbsp( ) 11 RSV_IRAP_11 Reserved IRAP VCL NALunit type VCL 12 OPI_NUT Operating point information non-VCLoperating_point_information_rbsp( ) 13 DCI_NUT Decoding capabilityinformation non-VCL decoding_capability_information_rbsp( ) 14 VPS_NUTVideo parameter set non-VCL video_parameter_set_rbsp( ) 15 SPS_NUTSequence parameter set non-VCL seq_parameter_set_rbsp( ) 16 PPS_NUTPicture parameter set non-VCL pic_parameter_set_rbsp( ) 17PREFIX_APS_NUT Adaptation parameter set non-VCL 18 SUFFIX_APS_NUTadaptation_parameter_set_rbsp( ) 19 PH_NUT Picture header non-VCLpicture_header_rbsp( ) 20 AUD_NUT AU delimiter non-VCLaccess_unit_delimiter_rbsp( ) 21 EOS_NUT End of sequence non-VCLend_of_seq_rbsp( ) 22 EOB_NUT End of bitstream non-VCLend_of_bitstream_rbsp( ) 23 PREFIX_SEI_NUT Supplemental enhancementinformation non-VCL 24 SUFFIX_SEI_NUT sei_rbsp( ) 25 FD_NUT Filler datanon-VCL filler_data_rbsp( ) 26 RSV_NVCL_26 Reserved non-VCL NAL unittypes non-VCL 27 RSV_NVCL_27 28 . . . 31 UNSPEC_28 . . . Unspecifiednon-VCL NAL unit types non-VCL UNSPEC_31 *indicates a property of apicture when pps_mixed_nalu_types_in_pic_flag is equal to 0 and aproperty of the subpicture when pps_mixed_nalu_types_in_pic_flag isequal to 1. NOTE A clean random access (CRA) picture could haveassociated RASL or RADL pictures present in the bitstream. NOTE Aninstantaneous decoding refresh (IDR) picture having nal_unit_type equalto IDR_N_LP does not have associated leading pictures present in thebitstream. An IDR picture having nal_unit_type equal to IDR_W_RADL doesnot have associated RASL pictures present in the bitstream, but couldhave associated RADL pictures in the bitstream.

The value of nal_unit_type shall be the same for all VCL NAL units of asubpicture. A subpicture is referred to as having the same NAL unit typeas the VCL NAL units of the subpicture.

For VCL NAL units of any particular picture, the following applies:

-   -   If pps_mixed_nalu_types_in_pic_flag is equal to 0, the value of        nal_unit_type shall be the same for all VCL NAL units of a        picture, and a picture or a PU is referred to as having the same        NAL unit type as the coded slice NAL units of the picture or PU.    -   Otherwise (pps_mixed_nalu_types_in_pic_flag is equal to 1), all        of the following constraints apply:        -   The picture shall have at least two subpictures.        -   VCL NAL units of the picture shall have two or more            different nal_unit_type values.        -   There shall be no VCL NAL unit of the picture that has            nal_unit_type equal to GDR_NUT.        -   When a VCL NAL unit of the picture has nal_unit_type equal            to nalUnitTypeA that is equal to IDR_W_RADL, IDR_N_LP, or            CRA_NUT, other VCL NAL units of the picture shall all have            nal_unit_type equal to nalUnitTypeA or TRAIL_NUT.

The value of nal_unit_type shall be the same for all pictures in an IRAPor GDR AU.

When sps_video_parameter_set_id is greater than 0,vps_max_tid_il_ref_pics_plus1 [i][j] is equal to 0 for j equal toGeneralLayerIdx[nuh_layer_id] and any value of i in the range of j+1 tovps_max_layers_minus1, inclusive, and pps_mixed_nalu_types_in_pic_flagis equal to 1, the value of nal_unit_type shall not be equal toIDR_W_RADL, IDR_N_LP, or CRA_NUT.

It is a requirement of bitstream conformance that the followingconstraints apply:

-   -   When a picture is a leading picture of an IRAP picture, it shall        be a RADL or RASL picture.    -   When a subpicture is a leading subpicture of an IRAP subpicture,        it shall be a RADL or RASL subpicture.    -   When a picture is not a leading picture of an IRAP picture, it        shall not be a RADL or RASL picture.    -   When a subpicture is not a leading subpicture of an IRAP        subpicture, it shall not be a RADL or RASL subpicture.    -   No RASL pictures shall be present in the bitstream that are        associated with an IDR picture.    -   No RASL subpictures shall be present in the bitstream that are        associated with an IDR subpicture.    -   No RADL pictures shall be present in the bitstream that are        associated with an IDR picture having nal_unit_type equal to        IDR_N_LP.        -   NOTE—It is possible to perform random access at the position            of an IRAP AU by discarding all PUs before the IRAP AU (and            to correctly decode the non-RASL pictures in the IRAP AU and            all the subsequent AUs in decoding order), provided each            parameter set is available (either in the bitstream or by            external means not specified in this Specification) when it            is referenced.    -   No RADL subpictures shall be present in the bitstream that are        associated with an IDR subpicture having nal_unit_type equal to        IDR_N_LP.    -   Any picture, with nuh_layer_id equal to a particular value        layerId, that precedes an IRAP picture with nuh_layer_id equal        to layerId in decoding order shall precede the IRAP picture in        output order and shall precede any RADL picture associated with        the IRAP picture in output order.    -   Any subpicture, with nuh_layer_id equal to a particular value        layerId and subpicture index equal to a particular value        subpicIdx, that precedes, in decoding order, an IRAP subpicture        with nuh_layer_id equal to layerId and subpicture index equal to        subpicIdx shall precede, in output order, the IRAP subpicture        and all its associated RADL subpictures.    -   Any picture, with nuh_layer_id equal to a particular value        layerId, that precedes a recovery point picture with        nuh_layer_id equal to layerId in decoding order shall precede        the recovery point picture in output order.    -   Any subpicture, with nuh_layer_id equal to a particular value        layerId and subpicture index equal to a particular value        subpicIdx, that precedes, in decoding order, a subpicture with        nuh_layer_id equal to layerId and subpicture index equal to        subpicIdx in a recovery point picture shall precede that        subpicture in the recovery point picture in output order.    -   Any RASL picture associated with a CRA picture shall precede any        RADL picture associated with the CRA picture in output order.    -   Any RASL subpicture associated with a CRA subpicture shall        precede any RADL subpicture associated with the CRA subpicture        in output order.    -   Any RASL picture, with nuh_layer_id equal to a particular value        layerId, associated with a CRA picture shall follow, in output        order, any IRAP or GDR picture with nuh_layer_id equal to        layerId that precedes the CRA picture in decoding order.    -   Any RASL subpicture, with nuh_layer_id equal to a particular        value layerId and subpicture index equal to a particular value        subpicIdx, associated with a CRA subpicture shall follow, in        output order, any IRAP or GDR subpicture, with nuh_layer_id        equal to layerId and subpicture index equal to subpicIdx, that        precedes the CRA subpicture in decoding order.    -   If sps_field_seq_flag is equal to 0, the following applies: when        the current picture, with nuh_layer_id equal to a particular        value layerId, is a leading picture associated with an IRAP        picture, it shall precede, in decoding order, all non-leading        pictures that are associated with the same IRAP picture.        Otherwise (sps_field_seq_flag is equal to 1), let picA and picB        be the first and the last leading pictures, in decoding order,        associated with an IRAP picture, respectively, there shall be at        most one non-leading picture with nuh_layer_id equal to layerId        preceding picA in decoding order, and there shall be no        non-leading picture with nuh_layer_id equal to layerId between        picA and picB in decoding order.    -   If sps_field_seq_flag is equal to 0, the following applies: when        the current subpicture, with nuh_layer_id equal to a particular        value layerId and subpicture index equal to a particular value        subpicIdx, is a leading subpicture associated with an IRAP        subpicture, it shall precede, in decoding order, all non-leading        subpictures that are associated with the same IRAP subpicture.        Otherwise (sps_field_seq_flag is equal to 1), let subpicA and        subpicB be the first and the last leading subpictures, in        decoding order, associated with an IRAP subpicture,        respectively, there shall be at most one non-leading subpicture        with nuh_layer_id equal to layerId and subpicture index equal to        subpicIdx preceding subpicA in decoding order, and there shall        be no non-leading picture with nuh_layer_id equal to layerId and        subpicture index equal to subpicIdx between picA and picB in        decoding order.

It should be noted that generally, an Intra Random Access Point (IRAP)picture is a picture that does not refer to any pictures other thanitself for prediction in its decoding process. In JVET-S2001, an IRAPpicture may be a clean random access (CRA) picture or an instantaneousdecoder refresh (IDR) picture. In JVET-S2001, the first picture in thebitstream in decoding order must be an IRAP or a gradual decodingrefresh (GDR) picture. JVET-S2001 describes the concept of a leadingpicture, which is a picture that precedes the associated IRAP picture inoutput order. JVET-S2001 further describes the concept of a trailingpicture which is a non-IRAP picture that follows the associated IRAPpicture in output order. Trailing pictures associated with an IRAPpicture also follow the IRAP picture in decoding order. For IDRpictures, there are no trailing pictures that require reference to apicture decoded prior to the IDR picture. JVET-S2001 provides where aCRA picture may have leading pictures that follow the CRA picture indecoding order and contain inter picture prediction references topictures decoded prior to the CRA picture. Thus, when the CRA picture isused as a random access point these leading pictures may not bedecodable and are identified as random access skipped leading (RASL)pictures. The other type of picture that can follow an IRAP picture indecoding order and precede it in output order is the random accessdecodable leading (RADL) picture, which cannot contain references to anypictures that precede the IRAP picture in decoding order. A GDR picture,is a picture for which each VCL NAL unit has nal_unit_type equal toGDR_NUT. If the current picture is a GDR picture that is associated witha picture header which signals a syntax element recovery_poc_cnt andthere is a picture picA that follows the current GDR picture in decodingorder in the CLVS and that has PicOrderCntVal equal to thePicOrderCntVal of the current GDR picture plus the value ofrecovery_poc_cnt, the picture picA is referred to as the recovery pointpicture.

As provided in Table 2, a NAL unit may include a video parameter set(VPS) syntax structure. Table 3 illustrates the video parameter setsyntax structure provided in JVET-S2001.

TABLE 3 Descriptor video_parameter_set_rbsp( ) { vps_video_parameter_set_id u(4)  vps_max_layers_minus1 u(6) vps_max_sublayers_minus1 u(3)  if( vps_max_layers_minus1 > 0 &&vps_max_sublayers_minus1 > 0 )   vps_default_ptl_dpb_hrd_max_tid_flagu(1)  if( vps_max_layers_minus1 > 0 )   vps_all_independent_layers_flagu(1)  for( i = 0; i <= vps_max_layers_minus1; i++ ) {   vps_layer_id[ i] u(6)   if( i > 0 && !vps_all_independent_layers_flag ) {   vps_independent_layer_flag[ i ] u(1)    if(!vps_independent_layer_flag[ i ] ) {     vps_max_tid_ref_present_flag[ i] u(1)     for( j = 0; j < i; j++ ) {      vps_direct_ref_layer_flag[ i][ j ] u(1)      if( vps_max_tid_ref_present_flag[ i ] &&vps_direct_ref_layer_flag[ i ][ j ] )      vps_max_tid_il_ref_pics_plus1[ i ][ j ] u(3)     }    }   }  } if( vps_max_layers_minus1 > 0 ) {   if( vps_all_independent_layers_flag)    vps_each_layer_is_an_ols_flag u(1)   if(!vps_each_layer_is_an_ols_flag ) {    if(!vps_all_independent_layers_flag )     vps_ols_mode_idc u(2)    if(vps_ols_mode_idc = = 2 ) {     vps_num_output_layer_sets_minus2 u(8)    for( i = 1; i <= vps_num_output_layer_sets_minus2 + 1; i ++ )     for( j = 0; j <= vps_max_layers_minus1; j++ )     vps_ols_output_layer_flag[ i ][ j ] u(1)    }   }  vps_num_ptls_minus1 u(8)  }  for( i = 0; i <= vps_num_ptls_minus1; i++) {   if( i > 0)    vps_pt_present_flag[ i ] u(1)   if(!vps_default_ptl_dpb_hrd_max_tid_flag )    vps_ptl_max_tid[ i ] u(3)  } while( !byte_aligned( ) )   vps_ptl_alignment_zero_bit /* equal to 0 */f(1)  for( i = 0; i <= vps_num_ptls_minus1; i++ )   profile_tier_level(vps_pt_present_flag[ i ], vps_ptl_max_tid[ i ] )  for( i = 0; i <TotalNumOlss; i++ )   if( vps_num_ptls_minus1 > 0 &&vps_num_ptls_minus1 + 1 != TotalNumOlss )    vps_ols_ptl_idx[ i ] u(8) if( !vps_each_layer_is_an_ols_flag ) {   vps_num_dpb_params_minus1ue(v)   if( vps_max_sublayers_minus1 > 0 )   vps_sublayer_dpb_params_present_flag u(1)   for( i = 0; i <VpsNumDpbParams; i++ ) {    if( !vps_default_ptl_dpb_hrd_max_tid_flag )    vps_dpb_max_tid[ i ] u(3)    dpb_parameters( vps_dpb_max_tid[ i ],     vps_sublayer_dpb_params_present_flag )   }   for( i = 0; i <NumMultiLayerOlss; i++ ) {    vps_ols_dpb_pic_width[ i ] ue(v)   vps_ols_dpb_pic_height[ i ] ue(v)    vps_ols_dpb_chroma_format[ i ]u(2)    vps_ols_dpb_bitdepth_minus8[ i ] ue(v)    if( VpsNumDpbParams >1 && VpsNumDpbParams != NumMultiLayerOlss )     vps_ols_dpb_params_idx[i ] ue(v)   }   vps_timing_hrd_params_present_flag u(1)   if(vps_timing_hrd_params_present_flag ) {    general_timing_hrd_parameters()    if( vps_max_sublayers_minus1 > 0 )    vps_sublayer_cpb_params_present_flag u(1)   vps_num_ols_timing_hrd_params_minus1 ue(v)       for( i = 0; i <=vps_num_ols_timing_hrd_params_minus1; i++ ) {     if(!vps_default_ptl_dpb_hrd_max_tid_flag )      vps_hrd_max_tid[ i ] u(3)    firstSubLayer = vps_sublayer_cpb_params_present_flag ? 0 :vps_hrd_max_tid[ i ]     ols_timing_hrd_parameters( firstSubLayer,vps_hrd_max_tid[ i ] )    }    if(vps_num_ols_timing_hrd_params_minus1 > 0 &&     vps_num_ols_timing_hrd_params_minus1 + 1 != NumMultiLayerOlss )    for( i = 0; i < NumMultiLayerOlss; i++ )     vps_ols_timing_hrd_idx[ i ] ue(v)   }  }  vps_extension_flag u(1) if( vps_extension_flag )   while( more_rbsp_data( ) )   vps_extension_data_flag u(1)  rbsp_trailing_bits( ) }

With respect to Table 3, JVET-S2001 provides the following semantics:

A VPS RBSP shall be available to the decoding process prior to it beingreferenced, included in at least one AU with TemporalId equal to 0 orprovided through external means.

All VPS NAL units with a particular value of vps_video_parameter_set_idin a CVS shall have the same content.

-   vps_video_parameter_set_id provides an identifier for the VPS for    reference by other syntax elements. The value of    vps_video_parameter_set_id shall be greater than 0.-   vps_max_layers_minus1 plus 1 specifies the number of layers    specified by the VPS, which is the maximum allowed number of layers    in each CVS referring to the VPS.-   vps_max_sublayers_minus1 plus 1 specifies the maximum number of    temporal sublayers that may be present in a layer specified by the    VPS. The value of vps_max_sublayers_minus1 shall be in the range of    0 to 6, inclusive.-   vps_default_ptl_dpb_hrd_max_tid_flag equal to 1 specifies that the    syntax elements vps_ptl_max_tid[i], vps_dpb_max_tid[i], and    vps_hrd_max_tid[i] are not present and are inferred to be equal to    the default value vps_max_sublayers_minus1.    vps_default_ptl_dpb_hrd_max_tid_flag equal to 0 specifies that the    syntax elements vps_ptl_max_tid[i], vps_dpb_max_tid[i], and    vps_hrd_max_tid[i] are present. When not present, the value of    vps_default_ptl_dpb_hrd_max_tid_flag is inferred to be equal to 1.-   vps_all_independent_layers_flag equal to 1 specifies that all layers    specified by the VPS are independently coded without using    inter-layer prediction. vps_all_independent_layers_flag equal to 0    specifies that one or more of the layers specified by the VPS might    use inter-layer prediction. When not present, the value of    vps_all_independent_layers_flag is inferred to be equal to 1.-   vps_layer_id[i] specifies the nuh_layer_id value of the i-th layer.    For any two non-negative integer values of m and n, when m is less    than n, the value of vps_layer_id[m] shall be less than    vps_layer_id[n].-   vps_independent_layer_flag[i] equal to 1 specifies that the layer    with index i does not use inter-layer prediction.    vps_independent_layer_flag[i] equal to 0 specifies that the layer    with index i might use inter-layer prediction and the syntax    elements vps_direct_ref_layer_flag[i][j] for j in the range of 0 to    i−1, inclusive, are present in the VPS. When not present, the value    of vps_independent_layer_flag[i] is inferred to be equal to 1.-   vps_max_tid_ref_present_flag[i] equal to 1 specifies that the syntax    element vps_max_tid_il_ref_pics_plus1[i][j] could be present.    vps_max_tid_ref_present_flag[i] equal to 0 specifies that the syntax    element vps_max_tid_il_ref_pics_plus1[i][j] is not present.-   vps_direct_ref_layer_flag[i][j] equal to 0 specifies that the layer    with index j is not a direct reference layer for the layer with    index i. vps_direct_ref_layer_flag [i][j] equal to 1 specifies that    the layer with index j is a direct reference layer for the layer    with index i. When vps_direct_ref_layer_flag[i][j] is not present    for i and j in the range of 0 to vps_max_layers_minus1, inclusive,    it is inferred to be equal to 0. When vps_independent_layer_flag[i]    is equal to 0, there shall be at least one value of j in the range    of 0 to i−1, inclusive, such that the value of    vps_direct_ref_layer_flag[i][j] is equal to 1.

The variables NumDirectRefLayers[i], DirectRefLayerIdx[i][d],NumRefLayers[i], ReferenceLayerIdx[i][r], and LayerUsedAsRefLayerFlag[j]are derived as follows:

for( i = 0; i <= vps_max_layers_minus1; i++ ) {  for( j = 0; j <=vps_max_layers_minus1; j++ ) {   dependencyFlag[ i ][ j ] =vps_direct_ref_layer_flag[ i ][ j ]   for( k = 0; k < i; k++ )    if(vps_direct_ref_layer_flag[ i ][ k ] && dependencyFlag[ k ][ j ] )    dependencyFlag[ i ][ j ] = 1  }  LayerUsedAsRefLayerFlag[ i ] = 0 }for( i = 0; i <= vps_max_layers_minus1; i++ ) {  for( j = 0, d = 0, r =0; j <= vps_max_layers_minus1; j++ ) {   if( vps_direct_ref_layer_flag[i ][ j ] ) {    DirectRefLayerIdx[ i ][ d++ ] = j   LayerUsedAsRefLayerFlag[ j ] = 1   }   if( dependencyFlag[ i ][ j ] )   ReferenceLayerIdx[ i ][ r++ ] = j  }  NumDirectRefLayers[ i ] = d NumRefLayers[ i ] = r }

The variable GeneralLayerIdx[i], specifying the layer index of the layerwith nuh_layer_id equal to vps_layer_id[i], is derived as follows:

-   -   for (i=0; i<=vps_max_layers_minus1; i++)        -   GeneralLayerIdx[vps_layer_id[i]]=i

For any two different values of i and j, both in the range of 0 tovps_max_layers_minus1, inclusive, when dependencyFlag[i][j] equal to 1,it is a requirement of bitstream conformance that the values ofsps_chroma_format_idc and sps_bitdepth_minus8 that apply to the i-thlayer shall be equal to the values of sps_chroma_format_idc andsps_bitdepth_minus8, respectively, that apply to the j-th layer.

-   vps_max_tid_il_ref_pics_plus1[i][j] equal to 0 specifies that the    pictures of the j-th layer that are neither IRAP pictures nor GDR    pictures with ph_recovery_poc_cnt equal to 0 are not used as ILRPs    for decoding of pictures of the i-th layer.    vps_max_tid_il_ref_pics_plus1 [i][j] greater than 0 specifies that,    for decoding pictures of the i-th layer, no picture from the j-th    layer with Temporand greater than    vps_max_tid_il_ref_pics_plus1[i][j]−1 is used as ILRP and no APS    with nuh_layer_id equal to vps_layer_id[j] and TemporalId greater    than vps_max_tid_il_ref_pics_plus1[i][j]−1 is referenced. When not    present, the value of vps_max_tid_il_ref_pics_plus1[i][j] is    inferred to be equal to vps_max_sublayers_minus1+1.-   vps_each_layer_is_an_ols_flag equal to 1 specifies that each OLS    specified by the VPS contains only one layer and each layer    specified by the VPS is an OLS with the single included layer being    the only output layer. vps_each_layer_is_an_ols_flag equal to 0    specifies that at least one OLS specified by the VPS contains more    than one layer. If vps_max_layers_minus1 is equal to 0, the value of    vps_each_layer_is_an_ols_flag is inferred to be equal to 1.    Otherwise, when vps_all_independent_layers_flag is equal to 0, the    value of vps_each_layer_is_an_ols_flag is inferred to be equal to 0.-   vps_ols_mode_idc equal to 0 specifies that the total number of OLSs    specified by the VPS is equal to vps_max_layers_minus1+1, the i-th    OLS includes the layers with layer indices from 0 to i, inclusive,    and for each OLS only the highest layer in the OLS is an output    layer.-   vps_ols_mode_idc equal to 1 specifies that the total number of OLSs    specified by the VPS is equal to vps_max_layers_minus1+1, the i-th    OLS includes the layers with layer indices from 0 to i, inclusive,    and for each OLS all layers in the OLS are output layers.-   vps_ols_mode_idc equal to 2 specifies that the total number of OLSs    specified by the VPS is explicitly signalled and for each OLS the    output layers are explicitly signalled and other layers are the    layers that are direct or indirect reference layers of the output    layers of the OLS.

The value of vps_ols_mode_idc shall be in the range of 0 to 2,inclusive. The value 3 of vps_ols_mode_idc is reserved for future use byITU-T I ISO/IEC. Decoders conforming to this version of thisSpecification shall ignore the OLSs with vps_ols_mode_idc equal to 3.

When vps_all_independent_layers_flag is equal to 1 andvps_each_layer_is_an_ols_flag is equal to 0, the value ofvps_ols_mode_idc is inferred to be equal to 2.

-   vps_num_output_layer_sets_minus2 plus 2 specifies the total number    of OLSs specified by the VPS when vps_ols_mode_idc is equal to 2.

The variable olsModeIdc is derived as follows:

-   -   if (!vps_each_layer_is_an_ols_flag)        -   olsModeIdc=vps_ols_mode_idc    -   else        -   olsModeIdc=4

The variable TotalNumOlss, specifying the total number of OLSs specifiedby the VPS, is derived as follows:

-   -   if (olsModeIdc==4 I I olsModeIdc==0 I I olsModeIdc==1)        -   TotalNumOlss=vps_max_layers_minus1+1    -   else if (olsModeIdc==2)        -   TotalNumOlss=vps_num_output_layer_sets_minus2+2

-   vps_ols_output_layer_flag[i][j] equal to 1 specifies that the layer    with nuh_layer_id equal to vps_layer_id[j] is an output layer of the    i-th OLS when vps_ols_mode_idc is equal to 2.    vps_ols_output_layer_flag[i][j] equal to 0 specifies that the layer    with nuh_layer_id equal to vps_layer_id[j] is not an output layer of    the i-th OLS when vps_ols_mode_idc is equal to 2.

The variable NumOutputLayersInOls[i], specifying the number of outputlayers in the i-th OLS, the variable NumSubLayersInLayerinOLS[i][j],specifying the number of sublayers in the j-th layer in the i-th OLS,the variable OutputLayerIdInOls[i][j], specifying the nuh_layer_id valueof the j-th output layer in the i-th OLS, and the variableLayerUsedAsOutputLayerFlag[k], specifying whether the k-th layer is usedas an output layer in at least one OLS, are derived as follows:

NumOutputLayersInOls[ 0 ] = 1 OutputLayerIdInOls[ 0 ][ 0 ] =vps_layer_id[ 0 ] NumSubLayersInLayerInOLS[ 0 ][ 0 ] = vps_ptl_max_tid[vps_ols_ptl_idx[ 0 ] ] + 1 LayerUsedAsOutputLayerFlag[ 0 ] = 1 for( i =1; i <= vps_max_layers_minus1; i++ ) {  if( olsModeIdc = = 4 | |olsModeIdc < 2 )   LayerUsedAsOutputLayerFlag[ i ] = 1  else if(vps_ols_mode_idc = = 2 )   LayerUsedAsOutputLayerFlag[ i ] = 0  }  for(i = 1; i < TotalNumOlss; i++ )   if( olsModeIdc = = 4 | | olsModeIdc = =0 ) {    NumOutputLayersInOls[ i ] = 1    OutputLayerIdInOls[ i ][ 0 ] =vps_layer_id[ i ]    if( vps_each_layer_is_an_ols_flag )    NumSubLayersInLayerInOLS[ i ][ 0 ] = vps_ptl_max_tid[ vps_ols_ptl_    idx[ i ] ] + 1    else {     NumSubLayersInLayerInOLS[ i ][ i ] =vps_ptl_max_tid[ vps_ols_ptl_idx[ i ] ] + 1     for( k = i − 1; k >= 0;k− − ) {      NumSubLayersInLayerInOLS[ i ][ k ] = 0      for( m = k +1; m <= i; m++ ) {       maxSublayerNeeded = min(NumSubLayersInLayerInOLS[ i ][ m ],       vps_max_tid_il_ref_pics_plus1[ m ][ k ] )       if(vps_direct_ref_layer_flag[ m ][ k ] &&        NumSubLayersInLayerInOLS[i ][ k ] < maxSublayerNeeded )       NumSubLayersInLayerInOLS[ i ][ k ]= maxSublayerNeeded      }     }    } } else if( vps_ols_mode_idc = = 1) {  NumOutputLayersInOls[ i ] = i + 1  for( j = 0; j <NumOutputLayersInOls[ i ]; j++ ) {   OutputLayerIdInOls[ i ][ j ] =vps_layer_id[ j ]   NumSubLayersInLayerInOLS[ i ][ j ] =vps_ptl_max_tid[ vps_ols_ptl_idx[ i ] ] + 1  } } else if(vps_ols_mode_idc = = 2 ) {  for( j = 0; j <= vps_max_layers_minus1; j++) {   layerIncludedInOlsFlag[ i ][ j ] = 0   NumSubLayersInLayerInOLS[ i][ j ] = 0 } highestIncludedLayer = 0 for( k = 0, j = 0; k <=vps_max_layers_minus1; k++ )   if( vps_ols_output_layer_flag[ i ][ k ] ){    layerIncludedInOlsFlag[ i ][ k ] = 1    highestIncludedLayer = k   LayerUsedAsOutputLayerFlag[ k ] = 1    OutputLayerIdx[ i ][ j ] = k   OutputLayerIdInOls[ i ][ j++ ] = vps_layer_id[ k ]   NumSubLayersInLayerInOLS[ i ][ k ] = vps_ptl_max_tid[vps_ols_ptl_idx[ i ] ] + 1   } NumOutputLayersInOls[ i ] = j for( j = 0;j < NumOutputLayersInOls[ i ]; j++ ) {   idx = OutputLayerIdx[ i ][ j ]  for( k = 0; k < NumRefLayers[ idx ]; k++ ) {    if(!layerIncludedInOlsFlag[ i ][ ReferenceLayerIdx[ idx ][ k ] ] )   layerIncludedInOlsFlag[ i ][ ReferenceLayerIdx[ idx ][ k ] ] = 1   } }  for( k = highestIncludedLayer − 1; k >= 0; k− − )   if(layerIncludedInOlsFlag[ i ][ k ] && !vps_ols_output_layer_flag[ i ][ k ])    for( m = k + 1; m <= highestIncludedLayer; m++ ) {    maxSublayerNeeded = min( NumSubLayersInLayerInOLS[ i ][ m ],     vps_max_tid_il_ref_pics_plus1[ m ][ k ] )     if(vps_direct_ref_layer_flag[ m ][ k ] && layerIncludedInOlsFlag[ i ][ m ]&&      NumSubLayersInLayerInOLS[ i ][ k ] < maxSublayerNeeded )    NumSubLayersInLayerInOLS[ i ][ k ] = maxSublayerNeeded    } }

For each value of i in the range of 0 to vps_max_layers_minus1,inclusive, the values of LayerUsedAsRefLayerFlag[i] andLayerUsedAsOutputLayerFlag[i] shall not both be equal to 0. In otherwords, there shall be no layer that is neither an output layer of atleast one OLS nor a direct reference layer of any other layer.

For each OLS, there shall be at least one layer that is an output layer.In other words, for any value of i in the range of 0 to TotalNumOlss−1,inclusive, the value of NumOutputLayersInOls[i] shall be greater than orequal to 1.

The variable NumLayersInOls[i], specifying the number of layers in thei-th OLS, the variable LayerIdInOls[i][j], specifying the nuh_layer_idvalue of the j-th layer in the i-th OLS, the variable NumMultiLayerOlss,specifying the number of multi-layer OLSs (i.e., OLSs that contain morethan one layer), and the variable MultiLayerOlsIdx[i], specifying theindex to the list of multi-layer OLSs for the i-th OLS whenNumLayersInOls[i] is greater than 0, are derived as follows:

NumLayersInOls[ 0 ] = 1 LayerIdInOls[ 0 ][ 0 ] = vps_layer_id[ 0 ]NumMultiLayerOlss = 0 for( i = 1; i < TotalNumOlss; i++ ) {  if(vps_each_layer_is_an_ols_flag ) {   NumLayersInOls[ i ] = 1  LayerIdInOls[ i ][ 0 ] = vps_layer_id[ i ] } else if( vps_ols_mode_idc= = 0 | | vps_ols_mode_idc = = 1 ) {   NumLayersInOls[ i ] = i + 1  for( j = 0; j < NumLayersInOls[ i ]; j++ )    LayerIdInOls[ i ][ j ] =vps_layer_id[ j ] } else if( vps_ols_mode_idc = = 2 ) {     for( k = 0,j = 0; k <= vps_max_layers_minus1; k++ )      if(layerIncludedInOlsFlag[ i ][ k ] )       LayerIdInOls[ i ][ j++ ] =vps_layer_id[ k ]     NumLayersInOls[ i ] = j   }   if( NumLayersInOls[i ] > 1 ) {    MultiLayerOlsIdx[ i ] = NumMultiLayerOlss   NumMultiLayerOlss++   }  } NOTE The 0-th OLS contains only the lowestlayer (i.e., the layer with nuh_layer_id equal to vps_layer_id[ 0 ]) andfor the 0-th OLS the only included layer is output.

The lowest layer in each OLS shall be an independent layer. In otherwords, for each i in the range of 0 to TotalNumOlss−1, inclusive, thevalue of vps_independent_layer_flag[GeneralLayerIdx[LayerIdInOls[i][0]]]shall be equal to 1.

Each layer shall be included in at least one OLS specified by the VPS.In other words, for each layer with a particular value of nuh_layer_idnuhLayerId equal to one of vps_layer_id[k] for k in the range of 0 tovps_max_layers_minus1, inclusive, there shall be at least one pair ofvalues of i and j, where i is in the range of 0 to TotalNumOlss−1,inclusive, and j is in the range of NumLayersInOls[i]−1, inclusive, suchthat the value of LayerIdInOls[i][j] is equal to nuhLayerId.

-   vps_num_ptls_minus1 plus 1 specifies the number of    profile_tier_level( ) syntax structures in the VPS. The value of    vps_num_ptls_minus1 shall be less than TotalNumOlss. When not    present, the value of vps_num_ptls_minus1 is inferred to be equal to    0.-   vps_pt_present_flag[i] equal to 1 specifies that profile, tier, and    general constraints information are present in the i-th    profile_tier_level( ) syntax structure in the VPS.    vps_pt_present_flag[i] equal to 0 specifies that profile, tier, and    general constraints information are not present in the i-th    profile_tier_level( ) syntax structure in the VPS. The value of    vps_pt_present_flag[0] is inferred to be equal to 1. When    vps_pt_present_flag[i] is equal to 0, the profile, tier, and general    constraints information for the i-th profile_tier_level( ) syntax    structure in the VPS are inferred to be the same as that for the    (i−1)-th profile_tier_level( ) syntax structure in the VPS.-   vps_ptl_max_tid[i] specifies the TemporalId of the highest sublayer    representation for which the level information is present in the    i-th profile_tier_level( ) syntax structure in the VPS and the    TemporalId of the highest sublayer representation that is present in    the OLSs with OLS index olsIdx such that vps_ols_ptl_idx[olsIdx] is    equal to i. The value of vps_ptl_max_tid[i] shall be in the range of    0 to vps_max_sublayers_minus1, inclusive. When    vps_default_ptl_dpb_hrd_max_tid_flag is equal to 1, the value of    vps_ptl_max_tid[i] is inferred to be equal to    vps_max_sublayers_minus 1.-   vps_ptl_alignment_zero_bit shall be equal to 0.-   vps_ols_ptl_idx[i] specifies the index, to the list of    profile_tier_level( ) syntax structures in the VPS, of the    profile_tier_level( ) syntax structure that applies to the i-th OLS.    When present, the value of vps_ols_ptl_idx[i] shall be in the range    of 0 to vps_num_ptls_minus1, inclusive.

When not present, the value of vps_ols_ptl_idx[i] is inferred asfollows:

-   -   If vps_num_ptls_minus1 is equal to 0, the value of        vps_ols_ptl_idx[i] is inferred to be equal to 0.    -   Otherwise (vps_num_ptls_minus1 is greater than 0 and        vps_num_ptls_minus1+1 is equal to TotalNumOlss), the value of        vps_ols_ptl_idx[i] is inferred to be equal to i.

When NumLayersInOls[i] is equal to 1, the profile_tier_level( ) syntaxstructure that applies to the i-th OLS is also present in the SPSreferred to by the layer in the i-th OLS. It is a requirement ofbitstream conformance that, when NumLayersInOls[i] is equal to 1, theprofile_tier_level( ) syntax structures signalled in the VPS and in theSPS for the i-th OLS shall be identical.

Each profile_tier_level( ) syntax structure in the VPS shall be referredto by at least one value of vps_ols_ptl_idx[i] for i in the range of 0to TotalNumOlss−1, inclusive.

-   vps_num_dpb_params_minus1 plus 1, when present, specifies the number    of dpb_parameters( ) syntax structures in the VPS. The value of    vps_num_dpb_params_minus1 shall be in the range of 0 to    NumMultiLayerOlss−1, inclusive.

The variable VpsNumDpbParams, specifying the number of dpb_parameters( )syntax strutcures in the VPS, is derived as follows:

-   -   if (vps_each_layer_is_an_ols_flag)        -   VpsNumDpbParams=0    -   else        -   VpsNumDpbParams=vps_num_dpb_params_minus1+1

-   vps_sublayer_dpb_params_present_flag is used to control the presence    of dpb_max_dec_pic_buffering_minus1[j], dpb_max_num_reorder_pics[j],    and dpb_max_latency_increase_plus1[j] syntax elements in the    dpb_parameters( ) syntax structures in the VPS for j in range from 0    to vps_dpb_max_tid[i]−1, inclusive, when vps_dpb_max_tid[i] is    greater than 0. When not present, the value of    vps_sub_dpb_params_info_present_flag is inferred to be equal to 0.

-   vps_dpb_max_tid[i] specifies the TemporalId of the highest sublayer    representation for which the DPB parameters could be present in the    i-th dpb_parameters( ) syntax structure in the VPS. The value of    vps_dpb_max_tid[i] shall be in the range of 0 to    vps_max_sublayers_minus1, inclusive. When not present, the value of    vps_dpb_max_tid[i] is inferred to be equal to    vps_max_sublayers_minus1.

The value of vps_dpb_max_tid[vps_ols_dpb_params_idx[m]] shall be greaterthan or equal to vps_ptl_max_tid[vps_ols_ptl_idx[n]] for each m-thmulti-layer OLS for m from 0 to NumMultiLayerOlss−1, inclusive, and nbeing the OLS index of the m-th multi-layer OLS among all OLSs.

-   vps_ols_dpb_pic_width[i] specifies the width, in units of luma    samples, of each picture storage buffer for the i-th multi-layer    OLS.-   vps_ols_dpb_pic_height[i] specifies the height, in units of luma    samples, of each picture storage buffer for the i-th multi-layer    OLS.-   vps_ols_dpb_chroma_format[i] specifies the greatest allowed value of    sps_chroma_format_idc for all SPSs that are referred to by CLVSs in    the CVS for the i-th multi-layer OLS.-   vps_ols_dpb_bitdepth_minus8[i] specifies the greatest allowed value    of sps_bitdepth_minus8 for all SPSs that are referred to by CLVSs in    the CVS for the i-th multi-layer OLS. The value of    vps_ols_dpb_bitdepth_minus8[i] shall be in the range of 0 to 2,    inclusive.    -   NOTE—For decoding the i-th multi-layer OLS, the deoder could        safely allocate memory for the DPB according to the values of        the syntax elements vps_ols_dpb_pic_width[i],        vps_ols_dpb_pic_height[i], vps_ols_dpb_chroma_format[i], and        vps_ols_dpb_bitdepth_minus8[i].-   vps_ols_dpb_params_idx[i] specifies the index, to the list of    dpb_parameters( ) syntax structures in the VPS, of the    dpb_parameters( ) syntax structure that applies to the i-th    multi-layer OLS. When present, the value of    vps_ols_dpb_params_idx[i] shall be in the range of 0 to    VpsNumDpbParams−1, inclusive.

When vps_ols_dpb_params_idx[i] is not present, it is inferred asfollows:

-   -   If VpsNumDpbParams is equal to 1, the value of        vps_ols_dpb_params_idx[i] to be equal to 0.    -   Otherwise (VpsNumDpbParams is greater than 1 and equal to        NumMultiLayerOlss), the value of vps_ols_dpb_params_idx[i] is        inferred to be equal to i.

For a single-layer OLS, the applicable dpb_parameters( ) syntaxstructure is present in the SPS referred to by the layer in the OLS.

Each dpb_parameters( ) syntax structure in the VPS shall be referred toby at least one value of vps_ols_dpb_params_idx[i] for i in the range of0 to NumMultiLayerOlss−1, inclusive.

-   vps_timing_hrd_params_present_flag equal to 1 specifies that the VPS    contains a general_timing_hrd_parameters( ) syntax structure and    other HRD parameters. vps_timing_hrd_params_present_flag equal to 0    specifies that the VPS does not contain a    general_timing_hrd_parameters( ) syntax structure or other HRD    parameters.

When NumLayersInOls[i] is equal to 1, the general_timing_hrd_parameters() syntax structure and the ols_timing_hrd_parameters( ) syntax structurethat apply to the i-th OLS are present in the SPS referred to by thelayer in the i-th OLS.

-   vps_sublayer_cpb_params_present_flag equal to 1 specifies that the    i-th ols_timing_hrd_parameters( ) syntax structure in the VPS    contains HRD parameters for the sublayer representations with    TemporalId in the range of 0 to vps_hrd_max_tid[i], inclusive.    vps_sublayer_cpb_params_present_flag equal to 0 specifies that the    i-th ols_timing_hrd_parameters( ) syntax structure in the VPS    contains HRD parameters for the sublayer representation with    TemporalId equal to vps_hrd_max_tid[i] only. When    vps_max_sublayers_minus1 is equal to 0, the value of    vps_sublayer_cpb_params_present_flag is inferred to be equal to 0.

When vps_sublayer_cpb_params_present_flag is equal to 0, the HRDparameters for the sublayer representations with TemporalId in the rangeof 0 to vps_hrd_max_tid[i]−1, inclusive, are inferred to be the same asthat for the sublayer representation with TemporalId equal tovps_hrd_max_tid[i]. These include the HRD parameters starting from thefixed_pic_rate_general_flag[i] syntax element till thesublayer_hrd_parameters(i) syntax structure immediately under thecondition “if (general_vcl_hrd_params_present_flag)” in theols_timing_hrd_parameters syntax structure.

-   vps_num_ols_timing_hrd_params_minus1 plus 1 specifies the number of    ols_timing_hrd_parameters( ) syntax structures present in the VPS    when vps_timing_hrd_params_present_flag is equal to 1. The value of    vps_num_ols_timing_hrd_params_minus1 shall be in the range of 0 to    NumMultiLayerOlss−1, inclusive.-   vps_hrd_max_tid[i] specifies the TemporalId of the highest sublayer    representation for which the HRD parameters are contained in the    i-th ols_timing_hrd_parameters( ) syntax structure. The value of    vps_hrd_max_tid[i] shall be in the range of 0 to    vps_max_sublayers_minus1, inclusive. When not present, the value of    vps_hrd_max_tid[i] is inferred to be equal to    vps_max_sublayers_minus1.

The value of vps_hrd_max_tid[vps_ols_timing_hrd_idx[m]] shall be greaterthan or equal to vps_ptl_max_tid[vps_ols_ptl_idx[n]] for each m-thmulti-layer OLS for m from 0 to NumMultiLayerOlss−1, inclusive, and nbeing the OLS index of the m-th multi-layer OLS among all OLSs.

-   vps_ols_timing_hrd_idx[i] specifies the index, to the list of    ols_timing_hrd_parameters( ) syntax structures in the VPS, of the    ols_timing_hrd_parameters( ) syntax structure that applies to the    i-th multi-layer OLS. The value of vps_ols_timing_hrd_idx[i] shall    be in the range of 0 to vps_num_ols_timing_hrd_params_minus1,    inclusive. When vps_ols_timing_hrd_idx[i] is not present, it is    inferred as follows:    -   If vps_num_ols_timing_hrd_params_minus1 is equal to 0, the value        of vps_ols_timing_hrd_idx[[i] is inferred to be equal to 0.    -   Otherwise (vps_num_ols_timing_hrd_params_minus1+1 is greater        than 1 and equal to NumMultiLayerOlss), the value of        vps_ols_timing_hrd_idx[i] is inferred to be equal to i.

For a single-layer OLS, the applicable ols_timing_hrd_parameters( )syntax structure is present in the SPS referred to by the layer in theOLS.

Each ols_timing_hrd_parameters( ) syntax structure in the VPS shall bereferred to by at least one value of vps_ols_timing_hrd_idx[i] for i inthe range of 1 to NumMultiLayerOlss−1, inclusive.

-   vps_extension_flag equal to 0 specifies that no    vps_extension_data_flag syntax elements are present in the VPS RBSP    syntax structure. vps_extension_flag equal to 1 specifies that    vps_extension_data_flag syntax elements might be present in the VPS    RBSP syntax structure. vps_extension_flag shall be equal to 0 in    bitstreams conforming to this version of this Specification.    However, some use of vps_extension_flag equal to 1 could be    specified in some future version of this Specification, and decoders    conforming to this version of this Specification shall allow the    value of vps_extension_flag equal to 1 to appear in the syntax.-   vps_extension_data_flag could have any value. Its presence and value    do not affect the decoding process specified in this version of this    Specification. Decoders conforming to this version of this    Specification shall ignore all vps_extension_data_flag syntax    elements.

As provided in Table 2, a NAL unit may include a sequence parameter set(SPS) syntax structure. Table 4 illustrates the sequence parameter set(SPS) syntax structure provided in JVET-S2001.

TABLE 4 Descriptor seq_parameter_set_rbsp( ) {  sps_seq_parameter_set_idu(4)  sps_video_parameter_set_id u(4)  sps_max_sublayers_minus1 u(3) sps_chroma_format_idc u(2)  sps_log2_ctu_size_minus5 u(2) sps_ptl_dpb_hrd_params_present_flag u(1)  if(sps_ptl_dpb_hrd_params_present_flag )   profile_tier_level( 1,sps_max_sublayers_minus1 )  sps_gdr_enabled_flag u(1) sps_ref_pic_resampling_enabled_flag u(1)  if(sps_ref_pic_resampling_enabled_flag )  sps_res_change_in_clvs_allowed_flag u(1) sps_pic_width_max_in_luma_samples ue(v) sps_pic_height_max_in_luma_samples ue(v)  sps_conformance_window_flagu(1)  if( sps_conformance_window_flag ) {   sps_conf_win_left_offsetue(v)   sps_conf_win_right_offset ue(v)   sps_conf_win_top_offset ue(v)  sps_conf_win_bottom_offset ue(v)  }  sps_subpic_info_present_flag u(1) if( sps_subpic_info_present_flag ) {   sps_num_subpics_minus1 ue(v)  if( sps_num_subpics_minus1 > 0 ) {    sps_independent_subpics_flagu(1)    sps_subpic_same_size_flag u(1)   }   for( i = 0;sps_num_subpics_minus1 > 0 && i <= sps_num_subpics_minus1; i++ ) {   if( !sps_subpic_same_size_flag | | i = = 0 ) {     if( i > 0 &&sps_pic_width_max_in_luma_samples > CtbSizeY )     sps_subpic_ctu_top_left_x[ i ] u(v)     if( i > 0 &&sps_pic_height_max_in_luma_samples > CtbSizeY )     sps_subpic_ctu_top_left_y[ i ] u(v)     if( i <sps_num_subpics_minus1 &&       sps_pic_width_max_in_luma_samples >CtbSizeY )      sps_subpic_width_minus1[ i ] u(v)     if( i <sps_num_subpics_minus1 &&       sps_pic_height_max_in_luma_samples >CtbSizeY )      sps_subpic_height_minus1[ i ] u(v)    }    if(!sps_independent_subpics_flag) {     sps_subpic_treated_as_pic_flag[ i ]u(1)     sps_loop_filter_across_subpic_enabled_flag[ i ] u(1)    }   }  sps_subpic_id_len_minus1 ue(v)  sps_subpic_id_mapping_explicitly_signalled_flag u(1)   if(sps_subpic_id_mapping_explicitly_signalled_flag ) {   sps_subpic_id_mapping_present_flag u(1)    if(sps_subpic_id_mapping_present_flag )     for( i = 0; i <=sps_num_subpics_minus1; i++ )      sps_subpic_id[ i ] u(v)   }  } sps_bitdepth_minus8 ue(v)  sps_entropy_coding_sync_enabled_flag u(1) sps_entry_point_offsets_present_flag u(1) sps_log2_max_pic_order_cnt_lsb_minus4 u(4)  sps_poc_msb_cycle_flag u(1) if( sps_poc_msb_cycle_flag )   sps_poc_msb_cycle_len_minus1 ue(v) sps_num_extra_ph_bytes u(2)  for( i = 0; i < (sps_num_extra_ph_bytes *8 ); i++ )   sps_extra_ph_bit_present_flag[ i ] u(1) sps_num_extra_sh_bytes u(2)  for( i = 0; i < (sps_num_extra_sh_bytes *8 ); i++ )   sps_extra_sh_bit_present_flag[ i ] u(1)  if(sps_ptl_dpb_hrd_params_present_flag ) {   if( sps_max_sublayers_minus1 >0 )    sps_sublayer_dpb_params_flag u(1)   dpb_parameters(sps_max_sublayers_minus1, sps_sublayer_dpb_params_flag )  } sps_log2_min_luma_coding_block_size_minus2 ue(v) sps_partition_constraints_override_enabled_flag u(1) sps_log2_diff_min_qt_min_cb_intra_slice_luma ue(v) sps_max_mtt_hierarehy_depth_intra_slice_luma ue(v)  if(sps_max_mtt_hierarchy_depth_intra_slice_luma != 0 ) {  sps_log2_diff_max_bt_min_qt_intra_slice_luma ue(v)  sps_log2_diff_max_tt_min_qt_intra_slice_luma ue(v)  }  if(sps_chroma_format_idc != 0 )   sps_qtbtt_dual_tree_intra_flag u(1)  if(sps_qtbtt_dual_tree_intra_flag ) {  sps_log2_diff_min_qt_min_cb_intra_slice_chroma ue(v)  sps_max_mtt_hierarehy_depth_intra_slice_chroma ue(v)   if(sps_max_mtt_hierarchy_depth_intra_slice_chroma != 0 ) {   sps_log2_diff_max_bt_min_qt_intra_slice_chroma ue(v)   sps_log2_diff_max_tt_min_qt_intra_slice_chroma ue(v)   }  } sps_log2_diff_min_qt_min_cb_inter_slice ue(v) sps_max_mtt_hierarchy_depth_inter_slice ue(v)  if(sps_max_mtt_hierarchy_depth_inter_slice != 0 ) {  sps_log2_diff_max_bt_min_qt_inter_slice ue(v)  sps_log2_diff_max_tt_min_qt_inter_slice ue(v)  }  if( CtbSizeY > 32 )  sps_max_luma_transform_size_64_flag u(1) sps_transform_skip_enabled_flag u(1)  if(sps_transform_skip_enabled_flag ) {  sps_log2_transform_skip_max_size_minus2 ue(v)   sps_bdpcm_enabled_flagu(1)  }  sps_mts_enabled_flag u(1)  if( sps_mts_enabled_flag ) {  sps_explicit_mts_intra_enabled_flag u(1)  sps_explicit_mts_inter_enabled_flag u(1)  }  sps_lfnst_enabled_flagu(1)  if( sps_chroma_format_idc != 0 ) {   sps_joint_cbcr_enabled_flagu(1)   sps_same_qp_table_for_chroma_flag u(1)   numQpTables =sps_same_qp_table_for_chroma_flag ? 1 :    ( sps_joint_cbcr_enabled_flag? 3 : 2 )   for( i = 0; i < numQpTables; i++ ) {   sps_qp_table_start_minus26[ i ] se(v)   sps_num_points_in_qp_table_minus1[ i ] ue(v)    for( j = 0; j <=sps_num_points_in_qp_table_minus1[ i ]; j++ ) {    sps_delta_qp_in_val_minus1[ i ][ j ] ue(v)    sps_delta_qp_diff_val[ i ][ j ] ue(v)    }   }  } sps_sao_enabled_flag u(1)  sps_alf_enabled_flag u(1)  if(sps_alf_enabled_flag && sps_chroma_format_idc != 0 )  sps_ccalf_enabled_flag u(1)  sps_lmcs_enabled_flag u(1) sps_weighted_pred_flag u(1)  sps_weighted_bipred_flag u(1) sps_long_term_ref_pics_flag u(1)  if( sps_video_parameter_set_id > 0 )  sps_inter_layer_prediction_enabled_flag u(1)  sps_idr_rpl_present_flagu(1)  sps_rpl1_same_as_rpl0_flag u(1)  for( i = 0; i < (sps_rpl1_same_as_rpl0_flag ? 1 : 2 ); i++ ) {   sps_num_ref_pic_lists[ i] ue(v)   for( j = 0; j < sps_num_ref_pic_lists[ i ]; j++)   ref_pic_list_struct( i, j )  }  sps_ref_wraparound_enabled_flag u(1) sps_temporal_mvp_enabled_flag u(1)  if( sps_temporal_mvp_enabled_flag )  sps_sbtmvp_enabled_flag u(1)  sps_amvr_enabled_flag u(1) sps_bdof_enabled_flag u(1)  if( sps_bdof_enabled_flag )  sps_bdof_control_present_in_ph_flag u(1)  sps_smvd_enabled_flag u(1) sps_dmvr_enabled_flag u(1)  if( sps_dmvr_enabled_flag)  sps_dmvr_control_present_in_ph_flag u(1)  sps_mmvd_enabled_flag u(1) if( sps_mmvd_enabled_flag )   sps_mmvd_fullpel_only_enabled_flag u(1) sps_six_minus_max_num_merge_cand ue(v)  sps_sbt_enabled_flag u(1) sps_affine_enabled_flag u(1)  if( sps_affine_enabled_flag ) {  sps_five_minus_max_num_subblock_merge_cand ue(v)  sps_6param_affine_enabled_flag u(1)   if( sps_amvr_enabled_flag )   sps_affine_amvr_enabled_flag u(1)   sps_affine_prof_enabled_flag u(1)  if( sps_affine_prof_enabled_flag )   sps_prof_control_present_in_ph_flag u(1)  }  sps_bcw_enabled_flagu(1)  sps_ciip_enabled_flag u(1)  if( MaxNumMergeCand >= 2 ) {  sps_gpm_enabled_flag u(1)   if( sps_gpm_enabled_flag &&MaxNumMergeCand >= 3 )    sps_max_num_merge_cand_minus_max_num_gpm_candue(v)  }  sps_log2_parallel_merge_level_minus2 ue(v) sps_isp_enabled_flag u(1)  sps_mrl_enabled_flag u(1) sps_mip_enabled_flag u(1)  if( sps_chroma_format_idc != 0 )  sps_cclm_enabled_flag u(1)  if( sps_chroma_format_idc = = 1 ) {  sps_chroma_horizontal_collocated_flag u(1)  sps_chroma_vertical_collocated_flag u(1)  }  sps_palette_enabled_flagu(1)  if( sps_chroma_format_idc = = 3 &&!sps_max_luma_transform_size_64_flag )   sps_act_enabled_flag u(1)  if(sps_transform_skip_enabled_flag | | sps_palette_enabled_flag )  sps_min_qp_prime_ts ue(v)  sps_ibc_enabled_flag u(1)  if(sps_ibc_enabled_flag )   sps_six_minus_max_num_ibc_merge_cand ue(v) sps_ladf_enabled_flag u(1)  if( sps_ladf_enabled_flag ) {  sps_num_ladf_intervals_minus2 u(2)  sps_ladf_lowest_interval_qp_offset se(v)   for( i = 0; i <sps_num_ladf_intervals_minus2 + 1; i++ ) {    sps_ladf_qp_offset[ i ]se(v)    sps_ladf_delta_threshold_minus1[ i ] ue(v)   }  } sps_explicit_scaling_list_enabled_flag u(1)  if( sps_lfnst_enabled_flag&& sps_explicit_scaling_list_enabled_flag )  sps_scaling_matrix_for_lfnst_disabled_flag u(1)  if(sps_act_enabled_flag && sps_explicit_scaling_list_enabled_flag )  sps_scaling_matrix_for_alternative_colour_space_disabled_flag u(1) if( sps_scaling_matrix_for_alternative_colour_space_disabled_flag )  sps_scaling_matrix_designated_colour_space_flag u(1) sps_dep_quant_enabled_flag u(1)  sps_sign_data_hiding_enabled_flag u(1) sps_virtual_boundaries_enabled_flag u(1)  if(sps_virtual_boundaries_enabled_flag ) {  sps_virtual_boundaries_present_flag u(1)   if(sps_virtual_boundaries_present_flag ) {   sps_num_ver_virtual_boundaries ue(v)    for( i = 0; i <sps_num_ver_virtual_boundaries; i++ )    sps_virtual_boundary_pos_x_minus1[ i ] ue(v)   sps_num_hor_virtual_boundaries ue(v)    for( i = 0; i <sps_num_hor_virtual_boundaries; i++ )    sps_virtual_boundary_pos_y_minus1[ i ] ue(v)   }  }  if(sps_ptl_dpb_hrd_params_present_flag ) {  sps_timing_hrd_params_present_flag u(1)   if(sps_timing_hrd_params_present_flag ) {    general_timing_hrd_parameters()    if( sps_max_sublayers_minus1 > 0 )    sps_sublayer_cpb_params_present_flag u(1)    firstSubLayer =sps_sublayer_cpb_params_present_flag ? 0 :      sps_max_sublayers_minus1   ols_timing_hrd_parameters( firstSubLayer, sps_max_sublayers_minus1 )  }  }  sps_field_seq_flag u(1)  sps_vui_parameters_present_flag u(1) if( sps_vui_parameters_present_flag ) {   sps_vui_payload_size_minus1ue(v)   while( !byte_aligned( ) )    sps_vui_alignment_zero_bit f(1)  vui_payload( sps_vui_payload_size_minus1 + 1 )  }  sps_extension_flagu(1)  if( sps_extension_flag )   while( more_rbsp_data( ) )   sps_extension_data_flag u(1)  rbsp_trailing_bits( ) }

With respect to Table 4, JVET-S2001 provides the following semantics:

An SPS RBSP shall be available to the decoding process prior to it beingreferenced, included in at least one AU with TemporalId equal to 0 orprovided through external means.

All SPS NAL units with a particular value of sps_seq_parameter_set_id ina CVS shall have the same content.

-   sps_seq_parameter_set_id provides an identifier for the SPS for    reference by other syntax elements. SPS NAL units, regardless of the    nuh_layer_id values, share the same value space of    sps_seq_parameter_set_id. Let spsLayerId be the value of the    nuh_layer_id of a particular SPS NAL unit, and vclLayerId be the    value of the nuh_layer_id of a particular VCL NAL unit. The    particular VCL NAL unit shall not refer to the particular SPS NAL    unit unless spsLayerId is less than or equal to vclLayerId and all    OLSs specified by the VPS that contain the layer with nuh_layer_id    equal to vclLayerId also contain the layer with nuh_layer_id equal    to spsLayerId.

NOTE—In a CVS that contains only one layer, the nuh_layer_id ofreferenced SPSs is equal to the nuh_layer_id of the VCL NAL units.

-   sps_video_parameter_set_id, when greater than 0, specifies the value    of vps_video_parameter_set_id for the VPS referred to by the SPS.

When sps_video_parameter_set_id is equal to 0, the following applies:

-   -   The SPS does not refer to a VPS, and no VPS is referred to when        decoding each CLVS referring to the SPS.    -   The value of vps_max_layers_minus1 is inferred to be equal to 0.    -   The CVS shall contain only one layer (i.e., all VCL NAL unit in        the CVS shall have the same value of nuh_layer_id).    -   The value of GeneralLayerIdx[nuh_layer_id] is set equal to 0.    -   The value of        vps_independent_layer_flag[GeneralLayerIdx[nuh_layer_id] ] is        inferred to be equal to 1.    -   The value of TotalNumOlss is set equal to 1, the value of        NumLayersInOls[0] is set equal to 1, and value of        vps_layer_id[0] is inferred to be equal to the value of        nuh_layer_id of all the VCL NAL units, and the value of        LayerIdInOls[0][0] is set equal to vps_layer_id[0].    -   NOTE—When sps_video_parameter_set_id is equal to 0, the phrase        “layers specified by the VPS” used in the specification refers        to the only present layer that has nuh_layer_id equal to        vps_layer_id[0], and the phrase “OLSs specified by the VPS” used        in the specification refers to the only present OLS that has OLS        index equal to 0 and LayerIdInOls[0][0] equal to        vps_layer_id[0].

When vps_independent_layer_flag[GeneralLayerIdx[nuh_layer_id] ] is equalto 1, the SPS referred to by a CLVS with a particular nuh_layer_id valuenuhLayerId shall have nuh_layer_id equal to nuhLayerId.

The value of sps_video_parameter_set_id shall be the same in all SPSsthat are referred to by CLVSs in a CVS.

-   sps_max_sublayers_minus1 plus 1 specifies the maximum number of    temporal sublayers that could be present in each CLVS referring to    the SPS.

If sps_video_parameter_set_id is greater than 0, the value ofsps_max_sublayers_minus1 shall be in the range of 0 tovps_max_sublayers_minus1, inclusive.

Otherwise (sps_video_parameter_set_id is equal to 0), the followingapplies:

-   -   The value of sps_max_sublayers_minus1 shall be in the range of 0        to 6, inclusive.    -   The value of vps_max_sublayers_minus1 is inferred to be equal to        sps_max_sublayers_minus1.    -   The value of NumSubLayersInLayerInOLS[0][0] is inferred to be        equal to sps_max_sublayers_minus1+1.    -   The value of vps_ols_ptl_idx[0] is inferred to be equal to 0,        and the value of vps_ptl_max_tid[vps_ols_ptl_idx[0]], i.e.,        vps_ptl_max_tid[0], is inferred to be equal to        sps_max_sublayers_minus1.

-   sps_chroma_format_idc specifies the chroma sampling relative to the    luma sampling as specified in subclause 6.2. When    sps_video_parameter_set_id is greater than 0 and the SPS is    referenced by a layer that is included in the i-th multi-layer OLS    specified by the VPS for any i in the range of 0 to    NumMultiLayerOlss−1, inclusive, it is a requirement of bitstream    conformance that the value of sps_chroma_format_idc shall be less    than or equal to the value of vps_ols_dpb_chroma_format[i].

-   sps_log 2_ctu_size_minus5 plus 5 specifies the luma coding tree    block size of each CTU. The value of sps_log 2_ctu_size_minus5 shall    be in the range of 0 to 2, inclusive. The value 3 for sps_log    2_ctu_size_minus5 is reserved for future use by ITU-T I ISO/IEC.    Decoders conforming to this version of this Specification shall    ignore the CLVSs with sps_log 2_ctu_size_minus5 equal to 3.

The variables CtbLog 2SizeY and CtbSizeY are derived as follows:

-   -   CtbLog 2SizeY=sps_log 2_ctu_size_minus5+5    -   CtbSizeY=1<<CtbLog 2SizeY

-   sps_ptl_dpb_hrd_params_present_flag equal to 1 specifies that a    profile_tier_level( ) syntax structure and a dpb_parameters( )    syntax structure are present in the SPS, and a    general_timing_hrd_parameters( ) syntax structure and an    ols_timing_hrd_parameters( ) syntax structure could also be present    in the SPS. sps_ptl_dpb_hrd_params_present_flag equal to 0 specifies    that none of these four syntax structures is present in the SPS.

When sps_video_parameter_set_id is greater than 0 and there is an OLSthat contains only one layer with nuh_layer_id equal to the nuh_layer_idof the SPS, or when sps_video_parameter_set_id is equal to 0, the valueof sps_ptl_dpb_hrd_params_present_flag shall be equal to 1.

-   sps_gdr_enabled_flag equal to 1 specifies that GDR pictures are    enabled and could be present in the CLVS. sps_gdr_enabled_flag equal    to 0 specifies that GDR pictures are disabled and not present in the    CLVS.-   sps_ref_pic_resampling_enabled_flag equal to 1 specifies that    reference picture resampling is enabled and a current picture    referring to the SPS might have slices that refer to a reference    picture in an active entry of an RPL that has one or more of the    following seven parameters different than that of the current    picture: 1) pps_pic_width_in_luma_samples, 2)    pps_pic_height_in_luma_samples, 3) pps_scaling_win_left_offset, 4)    pps_scaling_win_right_offset, 5) pps_scaling_win_top_offset, 6)    pps_scaling_win_bottom_offset, and 7) sps_num_subpics_minus1.    sps_ref_pic_resampling_enabled_flag equal to 0 specifies that    reference picture resampling is disabled and no current picture    referring to the SPS has slices that refer to a reference picture in    an active entry of an RPL that has one or more of these seven    parameters different than that of the current picture.    -   NOTE—When sps_ref_pic_resampling_enabled_flag is equal to 1, for        a current picture the reference picture that has one or more of        these seven parameters different than that of the current        picture could either belong to the same layer or a different        layer than the layer containing the current picture.-   sps_res_change_in_clvs_allowed_flag equal to 1 specifies that the    picture spatial resolution might change within a CLVS referring to    the SPS. sps_res_change_in_clvs_allowed_flag equal to 0 specifies    that the picture spatial resolution does not change within any CLVS    referring to the SPS. When not present, the value of    sps_res_change_in_clvs_allowed_flag is inferred to be equal to 0.-   sps_pic_width_max_in_luma_samples specifies the maximum width, in    units of luma samples, of each decoded picture referring to the SPS.    sps_pic_width_max_in_luma_samples shall not be equal to 0 and shall    be an integer multiple of Max(8, MinCbSizeY).

When sps_video_parameter_set_id is greater than 0 and the SPS isreferenced by a layer that is included in the i-th multi-layer OLSspecified by the VPS for any i in the range of 0 to NumMultiLayerOlss−1,inclusive, it is a requirement of bitstream conformance that the valueof sps_pic_width_max_in_luma_samples shall be less than or equal to thevalue of vps_ols_dpb_pic_width[i].

-   sps_pic_height_max_in_luma_samples specifies the maximum height, in    units of luma samples, of each decoded picture referring to the SPS.    sps_pic_height_max_in_luma_samples shall not be equal to 0 and shall    be an integer multiple of Max(8, MinCbSizeY).

When sps_video_parameter_set_id is greater than 0 and the SPS isreferenced by a layer that is included in the i-th multi-layer OLSspecified by the VPS for any i in the range of 0 to NumMultiLayerOlss−1,inclusive, it is a requirement of bitstream conformance that the valueof sps_pic_height_max_in_luma_samples shall be less than or equal to thevalue of vps_ols_dpb_pic_height[i].

-   sps_conformance_window_flag equal to 1 indicates that the    conformance cropping window offset parameters follow next in the    SPS. sps_conformance_window_flag equal to 0 indicates that the    conformance cropping window offset parameters are not present in the    SPS.-   sps_conf_win_left_offset, sps_conf_win_right_offset,    sps_conf_win_top_offset, and sps_conf_win_bottom_offset specify the    cropping window that is applied to pictures with    pps_pic_width_in_luma_samples equal to    sps_pic_width_max_in_luma_samples and pps_pic_height_in_luma_samples    equal to sps_pic_height_max_in_luma_samples. When    sps_conformance_window_flag is equal to 0, the values of    sps_conf_win_left_offset, sps_conf_win_right_offset,    sps_conf_win_top_offset, and sps_conf_win_bottom_offset are inferred    to be equal to 0.

The conformance cropping window contains the luma samples withhorizontal picture coordinates from SubWidthC*sps_conf_win_left_offsettosps_pic_width_max_in_luma_samples−(SubWidthC*sps_conf_win_right_offset+1)and vertical picture coordinates from SubHeightC*sps_conf_win_top_offsettosps_pic_height_max_in_luma_samples−(SubHeightC*sps_conf_win_bottom_offset+1),inclusive.

The value ofSubWidthC*(sps_conf_win_left_offset+sps_conf_win_right_offset) shall beless than sps_pic_width_max_in_luma_samples, and the value ofSubHeightC*(sps_conf_win_top_offset+sps_conf_win_bottom_offset) shall beless than sps_pic_height_max_in_luma_samples.

When sps_chroma_format_idc is not equal to 0, the correspondingspecified samples of the two chroma arrays are the samples havingpicture coordinates (x/SubWidthC, y/SubHeightC), where (x, y) are thepicture coordinates of the specified luma samples.

-   -   NOTE—The conformance cropping window offset parameters are only        applied at the output. All internal decoding processes are        applied to the uncropped picture size.

-   sps_subpic_info_present_flag equal to 1 specifies that subpicture    information is present for the CLVS and there might be one or more    than one subpicture in each picture of the CLVS.    sps_subpic_info_present_flag equal to 0 specifies that subpicture    information is not present for the CLVS and there is only one    subpicture in each picture of the CLVS.

When sps_res_change_in_clvs_allowed_flag is equal to 1, the value ofsps_subpic_info_present_flag shall be equal to 0.

-   -   NOTE—When a bitstream is the result of a subpicture        sub-bitstream extraction process and contains only a subset of        the subpictures of the input bitstream to the subpicture        sub-bitstream extraction process, it might be required to set        the value of sps_subpic_info_present_flag equal to 1 in the RBSP        of the SPSs.

-   sps_num_subpics_minus1 plus 1 specifies the number of subpictures in    each picture in the CLVS. The value of sps_num_subpics_minus1 shall    be in the range of 0 to MaxSlicesPerAu−1, inclusive, where    MaxSlicesPerAu is specified. When not present, the value of    sps_num_subpics_minus1 is inferred to be equal to 0.

-   sps_independent_subpics_flag equal to 1 specifies that all    subpicture boundaries in the CLVS are treated as picture boundaries    and there is no loop filtering across the subpicture boundaries.    sps_independent_subpics_flag equal to 0 does not impose such a    constraint. When not present, the value of    sps_independent_subpics_flag is inferred to be equal to 1.

-   sps_subpic_same_size_flag equal to 1 specifies that all subpictures    in the CLVS have the same width specified by    sps_subpic_width_minus1[0] and the same height specified by    sps_subpic_height_minus1[0]. sps_subpic_same_size_flag equal to 0    does not impose such a constraint. When not present, the value of    sps_subpic_same_size_flag is inferred to be equal to 0.

Let the variable tmpWidthVal be set equal to(sps_pic_width_max_in_luma_samples+CtbSizeY−1)/CtbSizeY, and thevariable tmpHeightVal be set equal to(sps_pic_height_max_in_luma_samples+CtbSizeY−1)/CtbSizeY.

-   sps_subpic_ctu_top_left_x[i] specifies horizontal position of top    left CTU of i-th subpicture in unit of CtbSizeY. The length of the    syntax element is Ceil(Log 2(tmpWidthVal)) bits.

When not present, the value of sps_subpic_ctu_top_left_x[i] is inferredas follows:

-   -   If sps_subpic_same_size_flag is equal to 0 or i is equal to 0,        the value of sps_subpic_ctu_top_left_x[i] is inferred to be        equal to 0.    -   Otherwise, the value of sps_subpic_ctu_top_left_x[i] is inferred        to be equal to (i %        numSubpicCols)*(sps_subpic_width_minus[0]+1).

When sps_subpic_same_size_flag is equal to 1, the variablenumSubpicCols, specifying the number of subpicture columns in eachpicture in the CLVS, is derived as follows:

-   -   numSubpicCols=tmpWidthVal/(sps_subpic_width_minus1[0]+1)

When sps_subpic_same_size_flag is equal to 1, the value ofnumSubpicCols*tmpHeightVal/(sps_subpic_height_minus1[0]+1)−1 shall beequal to sps_num_subpics_minus1.

-   sps_subpic_ctu_top_left_y[i] specifies vertical position of top left    CTU of i-th subpicture in unit of CtbSizeY. The length of the syntax    element is Ceil(Log 2(tmpHeightVal)) bits.

When not present, the value of sps_subpic_ctu_top_left_y[i] is inferredas follows:

-   -   If sps_subpic_same_size_flag is equal to 0 or i is equal to 0,        the value of sps_subpic_ctu_top_left_y[i] is inferred to be        equal to 0.    -   Otherwise, the value of sps_subpic_ctu_top_left_y[i] is inferred        to be equal to        (i/numSubpicCols)*(sps_subpic_height_minus1[0]+1).

-   sps_subpic_width_minus1[i] plus 1 specifies the width of the i-th    subpicture in units of CtbSizeY. The length of the syntax element is    Ceil(Log 2(tmpWidthVal)) bits.

When not present, the value of sps_subpic_width_minus1[i] is inferred asfollows:

-   -   If sps_subpic_same_size_flag is equal to 0 or i is equal to 0,        the value of sps_subpic_width_minus1[i] is inferred to be equal        to tmpWidthVal−sps_subpic_ctu_top_left_x[i]−1.    -   Otherwise, the value of sps_subpic_width_minus1 [i] is inferred        to be equal to sps_subpic_width_minus1[0].

When sps_subpic_same_size_flag is equal to 1, the value of tmpWidthVal %(sps_subpic_width_minus 1[0]+1) shall be equal to 0.

-   sps_subpic_height_minus1[i] plus 1 specifies the height of the i-th    subpicture in units of CtbSizeY. The length of the syntax element is    Ceil(Log 2(tmpHeightVal)) bits.

When not present, the value of sps_subpic_height_minus1[i] is inferredas follows:

-   -   If sps_subpic_same_size_flag is equal to 0 or i is equal to 0,        the value of sps_subpic_height_minus1 [i] is inferred to be        equal to tmpHeightVal−sps_subpic_ctu_top_left_y[i]−1.    -   Otherwise, the value of sps_subpic_height_minus1[i] is inferred        to be equal to sps_subpic_height_minus1[0].

When sps_subpic_same_size_flag is equal to 1, the value of tmpHeightVal% (sps_subpic_height_minus1[0]+1) shall be equal to 0.

It is a requirement of bitstream conformance that the shapes of thesubpictures shall be such that each subpicture, when decoded, shall haveits entire left boundary and entire top boundary consisting of pictureboundaries or consisting of boundaries of previously decodedsubpictures.

For each subpicture with subpicture index i in the range of 0 tosps_num_subpics_minus1, inclusive, it is a requirement of bitstreamconformance that all of the following conditions are true:

-   -   The value of (sps_subpic_ctu_top_left_x[i] *CtbSizeY) shall be        less than        (sps_pic_width_max_in_luma_samples−sps_conf_win_right_offset*SubWidthC).    -   The value of        ((sps_subpic_ctu_top_left_x[i]+sps_subpic_width_minus1        [i]+1)*CtbSizeY) shall be greater than        (sps_conf_win_left_offset*SubWidthC).    -   The value of (sps_subpic_ctu_top_left_y[i] *CtbSizeY) shall be        less than        (sps_pic_height_max_in_luma_samples−sps_conf_win_bottom_offset*SubHeightC).    -   The value of        ((sps_subpic_ctu_top_left_y[i]+sps_subpic_height_minus1[i]+1)*CtbSizeY)        shall be greater than (sps_conf_win_top_offset*SubHeightC).

-   sps_subpic_treated_as_pic_flag[i] equal to 1 specifies that the i-th    subpicture of each coded picture in the CLVS is treated as a picture    in the decoding process excluding in-loop filtering operations.

-   sps_subpic_treated_as_pic_flag[i] equal to 0 specifies that the i-th    subpicture of each coded picture in the CLVS is not treated as a    picture in the decoding process excluding in-loop filtering    operations. When not present, the value of    sps_subpic_treated_as_pic_flag[i] is inferred to be equal to 1.

-   sps_loop_filter_across_subpic_enabled_flag[i] equal to 1 specifies    that in-loop filtering operations across subpicture boundaries is    enabled and might be performed across the boundaries of the i-th    subpicture in each coded picture in the CLVS.    sps_loop_filter_across_subpic_enabled_flag[i] equal to 0 specifies    that in-loop filtering operations across subpicture boundaries is    disabled and are not performed across the boundaries of the i-th    subpicture in each coded picture in the CLVS. When not present, the    value of sps_loop_filter_across_subpic_enabled_pic_flag[i] is    inferred to be equal to 0.

-   sps_subpic_id_len_minus1 plus 1 specifies the number of bits used to    represent the syntax element sps_subpic_id[i], the syntax elements    pps_subpic_id[i], when present, and the syntax element sh_subpic_id,    when present. The value of sps_subpic_id_len_minus1 shall be in the    range of 0 to 15, inclusive. The value of    1<<(sps_subpic_id_len_minus1+1) shall be greater than or equal to    sps_num_subpics_minus1+1.

-   sps_subpic_id_mapping_explicitly_signalled_flag equal to 1 specifies    that the subpicture ID mapping is explicitly signalled, either in    the SPS or in the PPSs referred to by coded pictures of the CLVS.    sps_subpic_id_mapping_explicitly_signalled_flag equal to 0 specifies    that the subpicture ID mapping is not explicitly signalled for the    CLVS. When not present, the value of    sps_subpic_id_mapping_explicitly_signalled_flag is inferred to be    equal to 0.

-   sps_subpic_id_mapping_present_flag equal to 1 specifies that the    subpicture ID mapping is signalled in the SPS when    sps_subpic_id_mapping_explicitly_signalled_flag is equal to 1.    sps_subpic_id_mapping_present_flag equal to 0 specifies that    subpicture ID mapping is signalled in the PPSs referred to by coded    pictures of the CLVS when    sps_subpic_id_mapping_explicitly_signalled_flag is equal to 1.

-   sps_subpic_id[i] specifies the subpicture ID of the i-th subpicture.    The length of the sps_subpic_id[i] syntax element is    sps_subpic_id_len_minus1+1 bits.

-   sps_bitdepth_minus8 specifies the bit depth of the samples of the    luma and chroma arrays, BitDepth, and the value of the luma and    chroma quantization parameter range offset, QpBdOffset, as follows:    -   BitDepth=8+sps_bitdepth_minus8    -   QpBdOffset=6*sps_bitdepth_minus8

-   sps_bitdepth_minus8 shall be in the range of 0 to 2, inclusive.

When sps_video_parameter_set_id is greater than 0 and the SPS isreferenced by a layer that is included in the i-th multi-layer OLSspecified by the VPS for any i in the range of 0 to NumMultiLayerOlss−1,inclusive, it is a requirement of bitstream conformance that the valueof sps_bitdepth_minus8 shall be less than or equal to the value ofvps_ols_dpb_bitdepth_minus8[i].

-   sps_entropy_coding_sync_enabled_flag equal to 1 specifies that a    specific synchronization process for context variables is invoked    before decoding the CTU that includes the first CTB of a row of CTBs    in each tile in each picture referring to the SPS, and a specific    storage process for context variables is invoked after decoding the    CTU that includes the first CTB of a row of CTBs in each tile in    each picture referring to the SPS.    sps_entropy_coding_sync_enabled_flag equal to 0 specifies that no    specific synchronization process for context variables is required    to be invoked before decoding the CTU that includes the first CTB of    a row of CTBs in each tile in each picture referring to the SPS, and    no specific storage process for context variables is required to be    invoked after decoding the CTU that includes the first CTB of a row    of CTBs in each tile in each picture referring to the SPS.    -   NOTE—When sps_entropy_coding_sync_enabled_flag is equal to 1,        the so-called wavefront parallel processing (WPP) is enabled.-   sps_entry_point_offsets_present_flag equal to 1 specifies that    signalling for entry point offsets for tiles or tile-specific CTU    rows could be present in the slice headers of pictures referring to    the SPS. sps_entry_point_offsets_present_flag equal to 0 specifies    that signalling for entry point offsets for tiles or tile-specific    CTU rows are not present in the slice headers of pictures referring    to the SPS.-   sps_log 2_max_pic_order_cnt_lsb_minus4 specifies the value of the    variable MaxPicOrderCntLsb that is used in the decoding process for    picture order count as follows:    -   MaxPicOrderCntLsb=2^((sps_log) 2_max_pic_order_cnt_lsb_minus4+4)

The value of sps_log 2_max_pic_order_cnt_lsb_minus4 shall be in therange of 0 to 12, inclusive.

-   sps_poc_msb_cycle_flag equal to 1 specifies that the    ph_poc_msb_cycle_present_flag syntax element is present in PH syntax    structures referring to the SPS. sps_poc_msb_cycle_flag equal to 0    specifies that the ph_poc_msb_cycle_present_flag syntax element is    not present in PH syntax structures referring to the SPS.-   sps_poc_msb_cycle_len_minus1 plus 1 specifies the length, in bits,    of the ph_poc_msb_cycle_val syntax elements, when present in PH    syntax structures referring to the SPS. The value of    sps_poc_msb_cycle_len_minus1 shall be in the range of 0 to    32−sps_log 2_max_pic_order_cnt_lsb_minus4−5, inclusive.-   sps_num_extra_ph_bytes specifies the number of bytes of extra bits    in the PH syntax structure for coded pictures referring to the SPS.    The value of sps_num_extra_ph_bytes shall be equal to 0 in    bitstreams conforming to this version of this Specification.    Although the value of sps_num_extra_ph_bytes is required to be equal    to 0 in this version of this Specification, decoders conforming to    this version of this Specification shall allow the value of    sps_num_extra_ph_bytes equal to 1 or 2 to appear in the syntax.-   sps_extra_ph_bit_present_flag[i] equal to 1 specifies that the i-th    extra bit is present in PH syntax structures referring to the SPS.    sps_extra_ph_bit_present_flag[i] equal to 0 specifies that the i-th    extra bit is not present in PH syntax structures referring to the    SPS.

The variable NumExtraPhBits is derived as follows:

-   -   NumExtraPhBits=0    -   for (i=0; i<(sps_num_extra_ph_bytes*8); i++)        -   if (sps_extra_ph_bit_present_flag[i])            -   NumExtraPhBits++

-   sps_num_extra_sh_bytes specifies the number of bytes of extra bits    in the slice headers for coded pictures referring to the SPS. The    value of sps_num_extra_sh_bytes shall be equal to 0 in bitstreams    conforming to this version of this Specification. Although the value    of sps_num_extra_sh_bytes is required to be equal to 0 in this    version of this Specification, decoders conforming to this version    of this Specification shall allow the value of    sps_num_extra_sh_bytes equal to 1 or 2 to appear in the syntax.

-   sps_extra_sh_bit_present_flag[i] equal to 1 specifies that the i-th    extra bit is present in the slice headers of pictures referring to    the SPS. sps_extra_sh_bit_present_flag[i] equal to 0 specifies that    the i-th extra bit is not present in the slice headers of pictures    referring to the SPS.

The variable NumExtraShBits is derived as follows:

-   -   NumExtraShBits=0    -   for (i=0; i<(sps_num_extra_sh_bytes*8); i++)        -   if (sps_extra_sh_bit_present_flag[i)            -   NumExtraShBits++

-   sps_sublayer_dpb_params_flag is used to control the presence of    dpb_max_dec_pic_buffering_minusfl i], dpb_max_num_reorder_pics[i],    and dpb_max_latency_increase_plus1[i] syntax elements in the    dpb_parameters( ) syntax strucure in the SPS for i in range from 0    to sps_max_sublayers_minus1 1, inclusive, when    sps_max_sublayers_minus1 is greater than 0. When not present, the    value of sps_sublayer_dpb_params_flag is inferred to be equal to 0.

-   sps_log 2_min_luma_coding_block_size_minus2 plus 2 specifies the    minimum luma coding block size. The value range of sps_log    2_min_luma_coding_block_size_minus2 shall be in the range of 0 to    Min(4, sps_log 2_ctu_size_minus5+3), inclusive.

The variables MinCbLog 2SizeY, MinCbSizeY, IbcBufWidthY, IbcBufWidthCand Vsize are derived as follows:

-   -   MinCbLog 2SizeY=sps_log 2_min_luma_coding_block_size_minus2+2    -   MinCbSizeY=1<<MinCbLog 2SizeY    -   IbcBufWidthY=256*128/CtbSizeY    -   IbcBufWidthC=IbcBufWidthY/SubWidthC    -   VSize=Min(64,CtbSizeY)

The value of MinCbSizeY shall less than or equal to VSize.

The variables CtbWidthC and CtbHeightC, which specify the width andheight, respectively, of the array for each chroma CTB, are derived asfollows:

-   -   If sps_chroma_format_idc is equal to 0 (monochrome), CtbWidthC        and CtbHeightC are both set equal to 0.    -   Otherwise, CtbWidthC and CtbHeightC are derived as follows:    -   CtbWidthC=CtbSizeY/SubWidthC    -   CtbHeightC=CtbSizeY/SubHeightC

For log 2BlockWidth ranging from 0 to 4 and for log 2BlockHeight rangingfrom 0 to 4, inclusive, the up-right diagonal scan order arrayinitialization process as specified is invoked with 1<<log 2BlockWidthand 1<<log 2BlockHeight as inputs, and the output is assigned toDiagScanOrder[log 2BlockWidth][log 2BlockHeight].

For log 2BlockWidth ranging from 0 to 6 and for log 2BlockHeight rangingfrom 0 to 6, inclusive, the horizontal and vertical traverse scan orderarray initialization process as specified is invoked with 1<<log2BlockWidth and 1<<log 2BlockHeight as inputs, and the output isassigned to HorTravScanOrder[log 2BlockWidth][log 2BlockHeight] andVerTravScanOrder[log 2BlockWidth][log 2BlockHeight].

-   sps_partition_constraints_override_enabled_flag equal to 1 specifies    the presence of ph_partition_constraints_override_flag in PH syntax    structures referring to the SPS.    sps_partition_constraints_override_enabled_flag equal to 0 specifies    the absence of ph_partition_constraints_override_flag in PH syntax    structures referring to the SPS.-   sps_log 2_diff_min_qt_min_cb_intra_slice_luma specifies the default    difference between the base 2 logarithm of the minimum size in luma    samples of a luma leaf block resulting from quadtree splitting of a    CTU and the base 2 logarithm of the minimum coding block size in    luma samples for luma CUs in slices with sh_slice_type equal to    2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_min_qt_min_cb_intra_slice_luma present in PH syntax    structures referring to the SPS. The value of sps_log    2_diff_min_qt_min_cb_intra_slice_luma shall be in the range of 0 to    Min(6, CtbLog 2SizeY)−MinCbLog 2SizeY, inclusive. The base 2    logarithm of the minimum size in luma samples of a luma leaf block    resulting from quadtree splitting of a CTU is derived as follows:    -   MinQtLog 2SizeIntraY=sps_log        2_diff_min_qt_min_cb_intra_slice_luma+MinCbLog 2SizeY-   sps_max_mtt_hierarchy_depth_intra_slice_luma specifies the default    maximum hierarchy depth for coding units resulting from multi-type    tree splitting of a quadtree leaf in slices with sh_slice_type equal    to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default maximum hierarchy depth can be overridden by    ph_max_mtt_hierarchy_depth_intra_slice_luma present in PH syntax    structures referring to the SPS. The value of    sps_max_mtt_hierarchy_depth_intra_slice_luma shall be in the range    of 0 to 2*(CtbLog 2SizeY−MinCbLog 2SizeY), inclusive.-   sps_log 2_diff_max_bt_min_qt_intra_slice_luma specifies the default    difference between the base 2 logarithm of the maximum size (width    or height) in luma samples of a luma coding block that can be split    using a binary split and the base 2 logarithm of the minimum size    (width or height) in luma samples of a luma leaf block resulting    from quadtree splitting of a CTU in slices with sh_slice_type equal    to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_bt_min_qt_luma present in PH syntax structures referring    to the SPS. The value of sps_log    2_diff_max_bt_min_qt_intra_slice_luma shall be in the range of 0 to    CtbLog 2SizeY−MinQtLog 2SizeIntraY, inclusive. When sps_log    2_diff_max_bt_min_qt_intra_slice_luma is not present, the value of    sps_log 2_diff_max_bt_min_qt_intra_slice_luma is inferred to be    equal to 0.-   sps_log 2_diff_max_tt_min_qt_intra_slice_luma specifies the default    difference between the base 2 logarithm of the maximum size (width    or height) in luma samples of a luma coding block that can be split    using a ternary split and the base 2 logarithm of the minimum size    (width or height) in luma samples of a luma leaf block resulting    from quadtree splitting of a CTU in slices with sh_slice_type equal    to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_n_min_qt_luma present in PH syntax structures referring    to the SPS. The value of sps_log 2_diff    max_tt_min_qt_intra_slice_luma shall be in the range of 0 to Min(6,    CtbLog 2SizeY)−MinQtLog 2SizeIntraY, inclusive. When sps_log 2_diff    max_n_min_qt_intra_slice_luma is not present, the value of sps_log    2_diff_max_tt_min_qt_intra_slice_luma is inferred to be equal to 0.-   sps_qtbtt _dual_tree _intra _flag equal to 1 specifies that, for I    slices, each CTU is split into coding units with 64×64 luma samples    using an implicit quadtree split, and these coding units are the    root of two separate coding_tree syntax structure for luma and    chroma. sps_qtbtt_dual_tree_intra_flag equal to 0 specifies separate    coding_tree syntax structure is not used for I slices. When    sps_qtbtt_dual_tree_intra_flag is not present, it is inferred to be    equal to 0. When sps_log 2_diff_max_bt_min_qt_intra_slice_luma is    greater than Min(6, CtbLog 2SizeY)−MinQtLog 2SizeIntraY, the value    of sps_qtbtt_dual_tree_intra_flag shall be equal to 0.-   sps_log 2_diff_min_qt_min_cb_intra_slice_chroma specifies the    default difference between the base 2 logarithm of the minimum size    in luma samples of a chroma leaf block resulting from quadtree    splitting of a chroma CTU with treeType equal to DUAL_TREE_CHROMA    and the base 2 logarithm of the minimum coding block size in luma    samples for chroma CUs with treeType equal to DUAL_TREE_CHROMA in    slices with sh_slice_type equal to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_min_qt_min_cb_chroma present in PH syntax structures    referring to the SPS. The value of sps_log    2_diff_min_qt_min_cb_intra_slice_chroma shall be in the range of 0    to Min(6, CtbLog 2SizeY)−MinCbLog 2SizeY, inclusive. When not    present, the value of sps_log    2_diff_min_qt_min_cb_intra_slice_chroma is inferred to be equal    to 0. The base 2 logarithm of the minimum size in luma samples of a    chroma leaf block resulting from quadtree splitting of a CTU with    treeType equal to DUAL_TREE_CHROMA is derived as follows:    -   MinQtLog 2SizeIntraC=sps_log        2_diff_min_qt_min_cb_intra_slice_chroma+MinCbLog 2SizeY-   sps_max_mtt_hierarchy_depth_intra_slice_chroma specifies the default    maximum hierarchy depth for chroma coding units resulting from    multi-type tree splitting of a chroma quadtree leaf with treeType    equal to DUAL_TREE_CHROMA in slices with sh_slice_type equal to    2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default maximum hierarchy depth can be overridden by    ph_max_mtt_hierarchy_depth_chroma present in PH syntax structures    referring to the SPS. The value of    sps_max_mtt_hierarchy_depth_intra_slice_chroma shall be in the range    of 0 to 2*(CtbLog 2SizeY−MinCbLog 2SizeY), inclusive. When not    present, the value of sps_max_mtt_hierarchy_depth_intra_slice_chroma    is inferred to be equal to 0.-   sps_log 2_diff_max_bt_min_qt_intra_slice_chroma specifies the    default difference between the base 2 logarithm of the maximum size    (width or height) in luma samples of a chroma coding block that can    be split using a binary split and the base 2 logarithm of the    minimum size (width or height) in luma samples of a chroma leaf    block resulting from quadtree splitting of a chroma CTU with    treeType equal to DUAL_TREE_CHROMA in slices with sh_slice_type    equal to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_bt_min_qt_chroma present in PH syntax structures    referring to the SPS. The value of sps_log    2_diff_max_bt_min_qt_intra_slice_chroma shall be in the range of 0    to Min(6, CtbLog 2SizeY)−MinQtLog 2SizeIntraC, inclusive. When    sps_log 2_diff_max_bt_min_qt_intra_slice_chroma is not present, the    value of sps_log 2_diff_max_bt_min_qt_intra_slice_chroma is inferred    to be equal to 0.-   sps_log 2_diff_max_tt_min_qt_intra_slice_chroma specifies the    default difference between the base 2 logarithm of the maximum size    (width or height) in luma samples of a chroma coding block that can    be split using a ternary split and the base 2 logarithm of the    minimum size (width or height) in luma samples of a chroma leaf    block resulting from quadtree splitting of a chroma CTU with    treeType equal to DUAL_TREE_CHROMA in slices with sh_slice_type    equal to 2 (I) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_n_min_qt_chroma present in PH syntax structures referring    to the SPS. The value of sps_log    2_diff_max_tt_min_qt_intra_slice_chroma shall be in the range of 0    to Min(6, CtbLog 2SizeY)−MinQtLog 2SizeIntraC, inclusive. When    sps_log 2_diff_max_tt_min_qt_intra_slice_chroma is not present, the    value of sps_log 2_diff_max_tt_min_qt_intra_slice_chroma is inferred    to be equal to 0.-   sps_log 2_diff_min_qt_min_cb_inter_slice specifies the default    difference between the base 2 logarithm of the minimum size in luma    samples of a luma leaf block resulting from quadtree splitting of a    CTU and the base 2 logarithm of the minimum luma coding block size    in luma samples for luma CUs in slices with sh_slice_type equal to    0 (B) or 1 (P) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log 2_diff    min_qt_min_cb_inter_slice present in PH syntax structures referring    to the SPS. The value of sps_log 2_diff min_qt_min_cb_inter_slice    shall be in the range of 0 to Min(6, CtbLog 2SizeY)−MinCbLog 2SizeY,    inclusive. The base 2 logarithm of the minimum size in luma samples    of a luma leaf block resulting from quadtree splitting of a CTU is    derived as follows:    -   MinQtLog 2SizeInterY=sps_log        2_diff_min_qt_min_cb_inter_slice+MinCbLog 2SizeY-   sps_max_mtt_hierarchy_depth_inter_slice specifies the default    maximum hierarchy depth for coding units resulting from multi-type    tree splitting of a quadtree leaf in slices with sh_slice_type equal    to 0 (B) or 1 (P) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default maximum hierarchy depth can be overridden by    ph_max_mtt_hierarchy_depth_inter_slice present in PH syntax    structures referring to the SPS. The value of    sps_max_mtt_hierarchy_depth_inter_slice shall be in the range of 0    to 2*(CtbLog 2SizeY−MinCbLog 2SizeY), inclusive.-   sps_log 2_diff_max_bt_min_qt_inter_slice specifies the default    difference between the base 2 logarithm of the maximum size (width    or height) in luma samples of a luma coding block that can be split    using a binary split and the base 2 logarithm of the minimum size    (width or height) in luma samples of a luma leaf block resulting    from quadtree splitting of a CTU in slices with sh_slice_type equal    to 0 (B) or 1 (P) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_bt_min_qt_luma present in PH syntax structures referring    to the SPS. The value of sps_log 2_diff_max_bt_min_qt_inter_slice    shall be in the range of 0 to CtbLog 2SizeY−MinQtLog 2SizeInterY,    inclusive. When sps_log 2_diff_max_bt_min_qt_inter_slice is not    present, the value of sps_log 2_diff_max_bt_min_qt_inter_slice is    inferred to be equal to 0.-   sps_log 2_diff_max_tt_min_qt_inter_slice specifies the default    difference between the base 2 logarithm of the maximum size (width    or height) in luma samples of a luma coding block that can be split    using a ternary split and the base 2 logarithm of the minimum size    (width or height) in luma samples of a luma leaf block resulting    from quadtree splitting of a CTU in slices with sh_slice_type equal    to 0 (B) or 1 (P) referring to the SPS. When    sps_partition_constraints_override_enabled_flag is equal to 1, the    default difference can be overridden by ph_log    2_diff_max_n_min_qt_luma present in PH syntax structures referring    to the SPS. The value of sps_log 2_diff_max_tt_min_qt_inter_slice    shall be in the range of 0 to Min(6, CtbLog 2SizeY)−MinQtLog    2SizeInterY, inclusive. When sps_log    2_diff_max_tt_min_qt_inter_slice is not present, the value of    sps_log 2_diff_max_tt_min_qt_inter_slice is inferred to be equal to    0.-   sps_max_luma_transform_size_64_flag equal to 1 specifies that the    maximum transform size in luma samples is equal to 64.    sps_max_luma_transform_size_64_flag equal to 0 specifies that the    maximum transform size in luma samples is equal to 32. When not    present, the value of sps_max_luma_transform_size_64_flag is    inferred to be equal to 0.

The variables MinTbLog 2SizeY, MaxTbLog 2SizeY, MinTbSizeY, andMaxTbSizeY are derived as follows:

-   -   MinTbLog 2SizeY=2    -   MaxTbLog 2SizeY=sps_max_luma_transform_size_64_flag?6: 5    -   MinTbSizeY=1<<MinTbLog 2SizeY    -   MaxTbSizeY=1<<MaxTbLog 2SizeY

-   sps_transform_skip_enabled_flag equal to 1 specifies that    transform_skip_flag could be present in the transform unit syntax.    sps_transform_skip_enabled_flag equal to 0 specifies that    transform_skip_flag is not present in the transform unit syntax.

-   sps_log 2_transform_skip_max_size_minus2 specifies the maximum block    size used for transform skip, and shall be in the range of 0 to 3,    inclusive.

The variable MaxTsSize is set equal to 1<<(sps_log2_transform_skip_max_size_minus2+2).

-   sps_bdpcm_enabled_flag equal to 1 specifies that    intra_bdpcm_luma_flag and intra_bdpcm_chroma_flag could be present    in the coding unit syntax for intra coding units.    sps_bdpcm_enabled_flag equal to 0 specifies that    intra_bdpcm_luma_flag and intra_bdpcm_chroma_flag are not present in    the coding unit syntax for intra coding units. When not present, the    value of sps_bdpcm_enabled_flag is inferred to be equal to 0.-   sps_mts_enabled_flag equal to 1 specifies that    sps_explicit_mts_intra_enabled_flag and    sps_explicit_mts_inter_enabled_flag are present in the SPS.    sps_mts_enabled_flag equal to 0 specifies that    sps_explicit_mts_intra_enabled_flag and    sps_explicit_mts_inter_enabled_flag are not present in the SPS.-   sps_explicit_mts_intra_enabled_flag equal to 1 specifies that    mts_idx could be present in the intra coding unit syntax of the    CLVS. sps_explicit_mts_intra_enabled_flag equal to 0 specifies that    mts_idx is not present in the intra coding unit syntax of the CLVS.    When not present, the value of sps_explicit_mts_intra_enabled_flag    is inferred to be equal to 0.-   sps_explicit_mts_inter_enabled_flag equal to 1 specifies that    mts_idx could be present in the inter coding unit syntax of the    CLVS. sps_explicit_mts_inter_enabled_flag equal to 0 specifies that    mts_idx is not present in the inter coding unit syntax of the CLVS.    When not present, the value of sps_explicit_mts_inter_enabled_flag    is inferred to be equal to 0.-   sps_lfnst_enabled_flag equal to 1 specifies that lfnst_idx could be    present in intra coding unit syntax. sps_lfnst_enabled_flag equal to    0 specifies that lfnst_idx is not present in intra coding unit    syntax.-   sps_joint_cbcr_enabled_flag equal to 1 specifies that the joint    coding of chroma residuals is enabled for the CLVS.    sps_joint_cbcr_enabled_flag equal to 0 specifies that the joint    coding of chroma residuals is disabled for the CLVS. When not    present, the value of sps_joint_cbcr_enabled_flag is inferred to be    equal to 0.-   sps_same_qp_table_for_chroma_flag equal to 1 specifies that only one    chroma QP mapping table is signalled and this table applies to Cb    and Cr residuals and additionally to joint Cb-Cr residuals when    sps_joint_cbcr_enabled_flag is equal to 1.    sps_same_qp_table_for_chroma_flag equal to 0 specifies that chroma    QP mapping tables, two for Cb and Cr, and one additional for joint    Cb-Cr when sps_joint_cbcr_enabled_flag is equal to 1, are signalled    in the SPS. When not present, the value of    sps_same_qp_table_for_chroma_flag is inferred to be equal to 1.-   sps_qp_table_start_minus26[i] plus 26 specifies the starting luma    and chroma QP used to describe the i-th chroma QP mapping table. The    value of sps_qp_table_start_minus26[i] shall be in the range of    −26−QpBdOffset to 36 inclusive. When not present, the value of    sps_qp_table_start_minus26[i] is inferred to be equal to 0.-   sps_num_points_in_qp_table_minus1[i] plus 1 specifies the number of    points used to describe the i-th chroma QP mapping table. The value    of sps_num_points_in_qp_table_minus1 [i] shall be in the range of 0    to 36−sps_qp_table_start_minus26[i], inclusive. When not present,    the value of sps_num_points_in_qp_table_minus1[0] is inferred to be    equal to 0.-   sps_delta_qp_in_val_minus1[i][j] specifies a delta value used to    derive the input coordinate of the j-th pivot point of the i-th    chroma QP mapping table. When not present, the value of    sps_delta_qp_in_val_minus1 [0][j] is inferred to be equal to 0.-   sps_delta_qp_diff_val[i][j] specifies a delta value used to derive    the output coordinate of the j-th pivot point of the i-th chroma QP    mapping table.

The i-th chroma QP mapping table ChromaQpTable[ i ] for i =0..numQpTables − 1 is derived as follows:  qpInVal[ i ][ 0 ] =sps_qp_table_start_minus26[ i ] + 26  qpOutVal[ i ][ 0 ] = qpInVal[ i ][0 ]  for( j = 0; j <= sps_num_points_in_qp_table_minus1[ i ]; j++ ) {  qpInVal[ i ][ j + 1 ] = qpInVal[ i ][ j ] +sps_delta_qp_in_val_minus1[ i ][ j ] + 1   qpOutVal[ i ][ j + 1 ] =qpOutVal[ i ][ j ] +    ( sps_delta_qp_in_val_minus1[ i ][ j ]{circumflex over ( )} sps_delta_qp_diff_val[ i ][ j ] )  } ChromaQpTable[ i ][ qpInVal[ i ][ 0 ] ] = qpOutVal[ i ][ 0 ]  for( k =qpInVal[ i ][ 0 ] − 1; k >= −QpBdOffset; k − − )   ChromaQpTable[ i ][ k] = Clip3( −QpBdOffset, 63, ChromaQpTable[ i ][ k + 1 ] − 1 )  for( j =0; j <= sps_num_points_in_qp_table_minus1[ i ]; j++ ) {   sh = (sps_delta_qp_in_val_minus1[ i ][ j ] + 1 ) >> 1   for( k = qpInVal[ i ][j ] + 1, m = 1; k <= qpInval[ i ][ j + 1 ]; k++, m++ )    ChromaQpTable[i ][ k ] = ChromaQpTable[ i ][ qpInVal[ i ][ j ] ] +    ( ( qpOutVal[ i][j + 1] − qpOutVal[ i ][j ] ) * m + sh ) / (sps_delta_qp_in_val_minus1[ i ][ j ] + 1 )   }   for( k = qpInVal[ i ][sps_num_points_in_qp_table_minus1[ i ] + 1 ] + 1; k <= 63; k++ )   ChromaQpTable[ i ][ k ] = Clip3( −QpBdOffset, 63, ChromaQpTable[ i ][k − 1 ] + 1 )

When sps_same_qp_table_for_chroma_flag is equal to 1,ChromaQpTable[1][k] and ChromaQpTable[2][k] are set equal toChromaQpTable[0][k] for kin the range of −QpBdOffset to 63, inclusive.

It is a requirement of bitstream conformance that the values ofqpInVal[i][j] and qpOutVal[i][j] shall be in the range of −QpBdOffset to63, inclusive for i in the range of 0 to numQpTables−1, inclusive, and jin the range of 0 to sps_num_points_in_qp_table_minus1[i]+1, inclusive.

-   sps_sao_enabled_flag equal to 1 specifies that SAO is enabled for    the CLVS. sps_sao_enabled_flag equal to 0 specifies that SAO is    disabled for the CLVS.-   sps_alf_enabled_flag equal to 1 specifies that ALF is enabled for    the CLVS. sps_alf_enabled_flag equal to 0 specifies that ALF is    disabled for the CLVS.-   sps_ccalf_enabled_flag equal to 1 specifies that CCALF is enabled    for the CLVS. sps_ccalf_enabled_flag equal to 0 specifies that CCALF    is disabled for the CLVS. When not present, the value of    sps_ccalf_enabled_flag is inferred to be equal to 0.-   sps_lmcs_enabled_flag equal to 1 specifies that LMCS is enabled for    the CLVS. sps_lmcs_enabled_flag equal to 0 specifies that LMCS is    disabled for the CLVS.-   sps_weighted_pred_flag equal to 1 specifies that weighted prediction    might be applied to P slices referring to the SPS.    sps_weighted_pred_flag equal to 0 specifies that weighted prediction    is not applied to P slices referring to the SPS.-   sps_weighted_bipred_flag equal to 1 specifies that explicit weighted    prediction might be applied to B slices referring to the SPS.    sps_weighted_bipred_flag equal to 0 specifies that explicit weighted    prediction is not applied to B slices referring to the SPS.-   sps_long_term_ref_pics_flag equal to 0 specifies that no LTRP is    used for inter prediction of any coded picture in the CLVS.    sps_long_term_ref_pics_flag equal to 1 specifies that LTRPs might be    used for inter prediction of one or more coded pictures in the CLVS.-   sps_inter_layer_prediction_enabled_flag equal to 1 specifies that    inter-layer prediction is enabled for the CLVS and ILRPs might be    used for inter prediction of one or more coded pictures in the CLVS.    sps_inter_layer_prediction_enabled_flag equal to 0 specifies that    inter-layer prediction is disabled for the CLVS and no ILRP is used    for inter prediction of any coded picture in the CLVS. When    sps_video_parameter_set_id is equal to 0, the value of    sps_inter_layer_prediction_enabled_flag is inferred to be equal    to 0. When vps_independent_layer_flag[GeneralLayerIdx[nuh_layer_id]    ] is equal to 1, the value of    sps_inter_layer_prediction_enabled_flag shall be equal to 0.-   sps_idr_rpl_present_flag equal to 1 specifies that RPL syntax    elements could be present in slice headers of slices with    nal_unit_type equal to IDR_N_LP or IDR_W_RADL.    sps_idr_rpl_present_flag equal to 0 specifies that RPL syntax    elements are not present in slice headers of slices with    nal_unit_type equal to IDR_N_LP or IDR_W_RADL.-   sps_rpl1_same_as_rp10_flag equal to 1 specifies that the syntax    element sps_num_ref_pic_lists[1] and the syntax structure    ref_pic_list_struct(1, rplsIdx) are not present and the following    applies:    -   The value of sps_num_ref_pic_lists[1] is inferred to be equal to        the value of sps_num_ref_pic_lists[0].    -   The value of each of syntax elements in ref_pic_list_struct(1,        rplsIdx) is inferred to be equal to the value of corresponding        syntax element in ref_pic_list_struct(0, rplsIdx) for rplsIdx        ranging from 0 to sps_num_ref_pic_lists[0]−1.-   sps_num_ref_pic_lists[i] specifies the number of the    ref_pic_list_struct(listIdx, rplsIdx) syntax structures with listIdx    equal to i included in the SPS. The value of    sps_num_ref_pic_lists[i] shall be in the range of 0 to 64,    inclusive.    -   NOTE—For each value of listIdx (equal to 0 or 1), a decoder        could allocate memory for a total number of        sps_num_ref_pic_lists[i]+1 ref_pic_list_struct(listIdx, rplsIdx)        syntax structures since there could be one        ref_pic_list_struct(listIdx, rplsIdx) syntax structure directly        signalled in the picture headers or slice headers of a current        picture.-   sps_ref_wraparound_enabled_flag equal to 1 specifies that horizontal    wrap-around motion compensation is enabled for the CLVS.    sps_ref_wraparound_enabled_flag equal to 0 specifies that horizontal    wrap-around motion compensation is disabled for the CLVS.

It is a requirement of bitstream conformance that, when there is one ormore values of i in the range of 0 to sps_num_subpics_minus1, inclusive,for which sps_subpic_treated_as_pic_flag[i] is equal to 1 andsps_subpic_width_minus1 [i] plus 1 is not equal to(sps_pic_width_max_in_luma_samples+CtbSizeY−1)>>CtbLog 2SizeY), thevalue of sps_ref_wraparound_enabled_flag shall be equal to 0.

-   sps_temporal_mvp_enabled_flag equal to 1 specifies that temporal    motion vector predictors are enabled for the CLVS.    sps_temporal_mvp_enabled_flag equal to 0 specifies that temporal    motion vector predictors are disabled for the CLVS.-   sps_sbtmvp_enabled_flag equal to 1 specifies that subblock-based    temporal motion vector predictors are enabled and might be used in    decoding of pictures with all slices having sh_slice_type not equal    to I in the CLVS. sps_sbtmvp_enabled_flag equal to 0 specifies that    subblock-based temporal motion vector predictors are disabled and    not used in decoding of pictures in the CLVS. When    sps_sbtmvp_enabled_flag is not present, it is inferred to be equal    to 0.-   sps_amvr_enabled_flag equal to 1 specifies that adaptive motion    vector difference resolution is enabled for the CVLS.    amvr_enabled_flag equal to 0 specifies that adaptive motion vector    difference resolution is disabled for the CLVS.-   sps_bdof_enabled_flag equal to 1 specifies that the bi-directional    optical flow inter prediction is enabled for the CLVS.    sps_bdof_enabled_flag equal to 0 specifies that the bi-directional    optical flow inter prediction is disabled for the CLVS.-   sps_bdof_control_present_in_ph_flag equal to 1 specifies that    ph_bdof_disabled_flag could be present in PH syntax structures    referring to the SPS. sps_bdof_control_present_in_ph_flag equal to 0    specifies that ph_bdof_disabled_flag is not present in PH syntax    structures referring to the SPS. When not present, the value of    sps_bdof_control_present_in_ph_flag is inferred to be equal to 0.-   sps_smvd_enabled_flag equal to 1 specifies that symmetric motion    vector difference is enabled for the CLVS. sps_smvd_enabled_flag    equal to 0 specifies that symmetric motion vector difference is    disabled for the CLVS.-   sps_dmvr_enabled_flag equal to 1 specifies that decoder motion    vector refinement based inter bi-prediction is enabled for the CLVS.    sps_dmvr_enabled_flag equal to 0 specifies that decoder motion    vector refinement based inter bi-prediction is disabled for the    CLVS.-   sps_dmvr_control_present_in_ph_flag equal to 1 specifies that    ph_dmvr_disabled_flag could be present in PH syntax structures    referring to the SPS. sps_dmvr_control_present_in_ph_flag equal to 0    specifies that ph_dmvr_disabled_flag is not present in PH syntax    structures referring to the SPS. When not present, the value of    sps_dmvr_control_present_in_ph_flag is inferred to be equal to 0.-   sps_mmvd_enabled_flag equal to 1 specifies that merge mode with    motion vector difference is enabled for the CLVS.    sps_mmvd_enabled_flag equal to 0 specifies that merge mode with    motion vector difference is disabled for the CLVS.-   sps_mmvd_fullpel_only_enabled_flag equal to 1 specifies that the    merge mode with motion vector difference using only integer sample    precision is enabled for the CLVS.    sps_mmvd_fullpel_enabled_only_flag equal to 0 specifies that the    merge mode with motion vector difference using only integer sample    precision is disabled for the CLVS. When not present, the value of    sps_mmvd_fullpel_only_enabled_flag is inferred to be equal to 0.-   sps_six_minus_max_num_merge_cand specifies the maximum number of    merging motion vector prediction (MVP) candidates supported in the    SPS subtracted from 6. The value of sps_six_minus_max_num_merge_cand    shall be in the range of 0 to 5, inclusive.

The maximum number of merging MVP candidates, MaxNumMergeCand, isderived as follows:

-   -   MaxNumMergeCand=6−sps_six_minus_max_num_merge_cand

-   sps_sbt_enabled_flag equal to 1 specifies that subblock transform    for inter-predicted CUs is enabled for the CLVS.    sps_sbt_enabled_flag equal to 0 specifies that subblock transform    for inter-predicted CUs is disabled for the CLVS.

-   sps_affine_enabled_flag equal to 1 specifies that the affine model    based motion compensation is enabled for the CLVS and    inter_affine_flag and cu_affine_type_flag could be present in the    coding unit syntax of the CLVS. sps_affine_enabled_flag equal to 0    specifies that the affine model based motion compensation is    disabled for the CLVS and inter_affine_flag and cu_affine_type_flag    are not present in the coding unit syntax of the CLVS.

-   sps_five_minus_max_num_subblock_merge_cand specifies the maximum    number of subblock-based merging motion vector prediction candidates    supported in the SPS subtracted from 5. The value of    sps_five_minus_max_num_subblock_merge_cand shall be in the range of    0 to 5−sps_sbtmvp_enabled_flag, inclusive.

-   sps_6param_affine_enabled_flag equal to 1 specifies that the    6-parameter affine model based motion compensation is enabled for    the CLVS. sps_6param_affine_enabled_flag equal to 0 specifies that    the 6-parameter affine model based motion compensation is disabled    for the CLVS. When not present, the value of    sps_6param_affine_enabled_flag is inferred to be equal to 0.

-   sps_affine_amvr_enabled_flag equal to 1 specifies that adaptive    motion vector difference resolution is enabled for the CLVS.    sps_affine_amvr_enabled_flag equal to 0 specifies that adaptive    motion vector difference resolution is disabled for the CLVS. When    not present, the value of sps_affine_amvr_enabled_flag is inferred    to be equal to 0.

-   sps_affine_prof_enabled_flag equal to 1 specifies that the affine    motion compensation refined with optical flow is enabled for the    CLVS. sps_affine_prof_enabled_flag equal to 0 specifies that the    affine motion compensation refined with optical flow is disabled for    the CLVS. When not present, the value of    sps_affine_prof_enabled_flag is inferred to be equal to 0.

-   sps_prof_control_present_in_ph_flag equal to 1 specifies that    ph_prof_disabled_flag could be present in PH syntax structures    referring to the SPS. sps_prof_control_present_in_ph_flag equal to 0    specifies that ph_prof_disabled_flag is not present in PH syntax    structures referring to the SPS. When    sps_prof_control_present_in_ph_flag is not present, the value of    sps_prof_control_present_in_ph_flag is inferred to be equal to 0.

-   sps_bcw_enabled_flag equal to 1 specifies that bi-prediction with CU    weights is enabled for the CLVS and bcw_idx could be present in the    coding unit syntax of the CLVS. sps_bcw_enabled_flag equal to 0    specifies that bi-prediction with CU weights is disabled for the    CLVS and bcw_idx is not present in the coding unit syntax of the    CLVS.

-   sps_ciip_enabled_flag equal to 1 specifies that ciip_flag could be    present in the coding unit syntax for inter coding units.    sps_ciip_enabled_flag equal to 0 specifies that ciip_flag is not    present in the coding unit syntax for inter coding units.

-   sps_gpm_enabled_flag equal to 1 specifies that the geometric    partition based motion compensation is enabled for the CLVS and    merge_gpm_partition_idx, merge_gpm_idx0, and merge_gpm_idx1 could be    present in the coding unit syntax of the CLVS. sps_gpm_enabled_flag    equal to 0 specifies that the geometric partition based motion    compensation is disabled for the CLVS and merge_gpm_partition_idx,    merge_gpm_idx0, and merge_gpm_idx1 are not present in the coding    unit syntax of the CLVS. When not present, the value of    sps_gpm_enabled_flag is inferred to be equal to 0.

-   sps_max_num_merge_cand_minus_max_num_gpm_cand specifies the maximum    number of geometric partitioning merge mode candidates supported in    the SPS subtracted from MaxNumMergeCand. The value of    sps_max_num_merge_cand_minus_max_num_gpm_cand shall be in the range    of 0 to MaxNumMergeCand−2, inclusive.

The maximum number of geometric partitioning merge mode candidates,MaxNumGpmMergeCand, is derived as follows:

-   -   if (sps_gpm_enabled_flag && MaxNumMergeCand>=3)        -   MaxNumGpmMergeCand=MaxNumMergeCand−            -   sps_max_num_merge_cand_minus_max_num_gpm_cand    -   else if (sps_gpm_enabled_flag && MaxNumMergeCand==2)        -   MaxNumGpmMergeCand=2    -   else        -   MaxNumGpmMergeCand=0

-   sps_log 2_parallel_merge_level_minus2 plus 2 specifies the value of    the variable Log 2ParMrgLevel, which is used in the derivation    process for spatial merging candidates as specified, the derivation    process for motion vectors and reference indices in subblock merge    mode as specified, and to control the invocation of the updating    process for the history-based motion vector predictor list. The    value of sps_log 2_parallel_merge_level_minus2 shall be in the range    of 0 to CtbLog 2SizeY−2, inclusive. The variable Log 2ParMrgLevel is    derived as follows:    -   Log 2ParMrgLevel=sps_log 2_parallel_merge_level_minus2+2

-   sps_isp_enabled_flag equal to 1 specifies that intra prediction with    subpartitions is enabled for the CLVS. sps_isp_enabled_flag equal to    0 specifies that intra prediction with subpartitions is disabled for    the CLVS.

-   sps_mrl_enabled_flag equal to 1 specifies that intra prediction with    multiple reference lines is enabled for the CLVS.    sps_mrl_enabled_flag equal to 0 specifies that intra prediction with    multiple reference lines is disabled for the CLVS.

-   sps_mip_enabled_flag equal to 1 specifies that the matrix-based    intra prediction is enabled for the CLVS. sps_mip_enabled_flag equal    to 0 specifies that the matrix-based intra prediction is disabled    for the CLVS.

-   sps_cclm_enabled_flag equal to 1 specifies that the cross-component    linear model intra prediction from luma component to chroma    component is enabled for the CLVS. sps_cclm_enabled_flag equal to 0    specifies that the cross-component linear model intra prediction    from luma component to chroma component is disabled for the CLVS.    When sps_cclm_enabled_flag is not present, it is inferred to be    equal to 0.

-   sps_chroma_horizontal_collocated_flag equal to 1 specifies that    prediction processes operate in a manner designed for chroma sample    positions that are not horizontally shifted relative to    corresponding luma sample positions.    sps_chroma_horizontal_collocated_flag equal to 0 specifies that    prediction processes operate in a manner designed for chroma sample    positions that are shifted to the right by 0.5 in units of luma    samples relative to corresponding luma sample positions. When    sps_chroma_horizontal_collocated_flag is not present, it is inferred    to be equal to 1.

-   sps_chroma_vertical_collocated_flag equal to 1 specifies that    prediction processes operate in a manner designed for chroma sample    positions that are not vertically shifted relative to corresponding    luma sample positions. sps_chroma_vertical_collocated_flag equal to    0 specifies that prediction processes operate in a manner designed    for chroma sample positions that are shifted downward by 0.5 in    units of luma samples relative to corresponding luma sample    positions. When sps_chroma_vertical_collocated_flag is not present,    it is inferred to be equal to 1.

-   sps_palette_enabled_flag equal to 1 specifies that the palette    prediction mode is enabled for the CLVS. sps_palette_enabled_flag    equal to 0 specifies that the palette prediction mode is disabled    for the CLVS. When sps_palette_enabled_flag is not present, it is    inferred to be equal to 0.

-   sps_act_enabled_flag equal to 1 specifies that the adaptive colour    transform is enabled for the CLVS and the cu_act_enabled_flag could    be present in the coding unit syntax of the CLVS.    sps_act_enabled_flag equal to 0 speifies that the adaptive colour    transform is disabled for the CLVS and cu_act_enabled_flag is not    present in the coding unit syntax of the CLVS. When    sps_act_enabled_flag is not present, it is inferred to be equal to    0.

-   sps_min_qp_prime_ts specifies the minimum allowed quantization    parameter for transform skip mode as follows:    -   QpPrimeTsMin=4+6*sps_min_qp_prime_ts

The value of sps_min_qp_prime_ts shall be in the range of 0 to 8,inclusive.

-   sps_ibc_enabled_flag equal to 1 specifies that the IBC prediction    mode is enabled for the CLVS. sps_ibc_enabled_flag equal to 0    specifies that the IBC prediction mode is disabled for the CLVS.    When sps_ibc_enabled_flag is not present, it is inferred to be equal    to 0.-   sps_six_minus_max_num_ibc_merge_cand, when sps_ibc_enabled_flag is    equal to 1, specifies the maximum number of IBC merging block vector    prediction (BVP) candidates supported in the SPS subtracted from 6.    The value of sps_six_minus_max_num_ibc_merge_cand shall be in the    range of 0 to 5, inclusive. The maximum number of IBC merging BVP    candidates, MaxNumIbcMergeCand, is derived as follows:    -   if (sps_ibc_enabled_flag)        -   MaxNumIbcMergeCand=6−sps_six_minus_max_num_ibc_merge_cand    -   else        -   MaxNumIbcMergeCand=0-   sps_ladf_enabled_flag equal to 1 specifies that    sps_num_ladf_intervals_minus2, sps_ladf_lowest_interval_qp_offset,    sps_ladf_qp_offset[i], and sps_ladf_delta_threshold_minus1[i] are    present in the SPS. sps_ladf_enabled_flag equal to 0 specifies that    sps_num_ladf_intervals_minus2, sps_ladf_lowest_interval_qp_offset,    sps_ladf_qp_offset[i], and sps_ladf_delta_threshold_minus1[i] are    not present in the SPS.-   sps_num_ladf_intervals_minus2 plus 2 specifies the number of    sps_ladf_delta_threshold_minus 1 [i] and sps_ladf_qp_offset[i]    syntax elements that are present in the SPS. The value of    sps_num_ladf_intervals_minus2 shall be in the range of 0 to 3,    inclusive.-   sps_ladf_lowest_interval_qp_offset specifies the offset used to    derive the variable qP as specified The value of    sps_ladf_lowest_interval_qp_offset shall be in the range of −63 to    63, inclusive.-   sps_ladf_qp_offset[i] specifies the offset array used to derive the    variable qP as specified. The value of sps_ladf_qp_offset[i] shall    be in the range of −63 to 63, inclusive.-   sps_ladf_delta_threshold_minus1[i] is used to compute the values of    SpsLadfIntervalLowerBound[i], which specifies the lower bound of the    i-th luma intensity level interval. The value of    sps_ladf_delta_threshold_minus1[i] shall be in the range of 0 to    2^(BitDepth)−3, inclusive.

The value of SpsLadfIntervalLowerBound[0] is set equal to 0.

For each value of i in the range of 0 to sps_num_ladf intervals_minus2,inclusive, the variable SpsLadfIntervalLowerBound[i+1] is derived asfollows:

-   -   SpsLadfIntervalLowerBound[i+1]=SpsLadfIntervalLowerBound[i]+sps_ladf_delta_threshold_minus1[i]+1

-   sps_explicit_scaling_list_enabled_flag equal to 1 specifies that the    use of an explicit scaling list, which is signalled in a scaling    list APS, in the scaling process for transform coefficients when    decoding a slice is enabled for the CLVS.    sps_explicit_scaling_list_enabled_flag equal to 0 specifies that the    use of an explicit scaling list in the scaling process for transform    coefficients when decoding a slice is disabled for the CLVS.

-   sps_scaling_matrix_for_lfnst_disabled_flag equal to 1 specifies that    scaling matrices are disabled for blocks coded with LFNST for the    CLVS. sps_scaling_matrix_for_lfnst_disabled_flag equal to 0    specifies that the scaling matrices is enabled for blocks coded with    LFNST for the CLVS.

-   sps_scaling_matrix_for_alternative_colour_space_disabled_flag equal    to 1 specifies, for the CLVS, that scaling matrices are disabled and    not applied to blocks of a coding unit when the decoded residuals of    the current coding unit are applied using a colour space conversion.    sps_scaling_matrix_for_alternative_colour_space_disabled_flag equal    to 0 specifies, for the CLVS, that scaling matrices are enabled and    could be applied to blocks of a coding unit when the decoded    residuals of the current coding unit are applied using a colour    space conversion. When not present, the value of    sps_scaling_matrix_for_alternative_colour_space_disabled_flag is    inferred to be equal to 0.

-   sps_scaling_matrix_designated_colour_space_flag equal to 1 specifies    that the colour space of the scaling matrices is the colour space    that does not use a colour space conversion for the decoded    residuals. sps_scaling_matrix_designated_colour_space_flag equal to    0 specifies that the designated colour space of the scaling matrices    is the colour space that uses a colour space conversion for the    decoded residuals.

-   sps_dep_quant_enabled_flag equal to 1 specifies that dependent    quantization is enabled for the CLVS. sps_dep_quant_enabled_flag    equal to 0 specifies that dependent quantization is disabled for the    CLVS.

-   sps_sign_data_hiding_enabled_flag equal to 1 specifies that sign bit    hiding is enabled for the CLVS. sps_sign_data_hiding_enabled_flag    equal to 0 specifies that sign bit hiding is disabled for the CLVS.

-   sps_virtual_boundaries_enabled_flag equal to 1 specifies that    disabling in-loop filtering across virtual boundaries is enabled for    the CLVS. sps_virtual_boundaries_enabled_flag equal to 0 specifies    that disabling in-loop filtering across virtual boundaries is    disabled for the CLVS. In-loop filtering operations include the    deblocking filter, sample adaptive offset filter, and adaptive loop    filter operations.

-   sps_virtual_boundaries_present_flag equal to 1 specifies that    information of virtual boundaries is signalled in the SPS.    sps_virtual_boundaries_present_flag equal to 0 specifies that    information of virtual boundaries is not signalled in the SPS. When    there is one or more than one virtual boundaries signalled in the    SPS, the in-loop filtering operations are disabled across the    virtual boundaries in pictures referring to the SPS. In-loop    filtering operations include the deblocking filter, sample adaptive    offset filter, and adaptive loop filter operations. When not    present, the value of sps_virtual_boundaries_present_flag is    inferred to be equal to 0.

When sps_res_change_in_clvs_allowed_flag is equal to 1, the value ofsps_virtual_boundaries_present_flag shall be equal to 0.

When sps_subpic_info_present_flag andsps_virtual_boundaries_enabled_flag are both equal to 1, the value ofsps_virtual_boundaries_present_flag shall be equal to 1.

-   sps_num_ver_virtual_boundaries specifies the number of    sps_virtual_boundary_pos_x_minus1 [i] syntax elements that are    present in the SPS. The value of sps_num_ver_virtual_boundaries    shall be in the range of 0 to (sps_pic_width_max_in_luma_samples<=8?    0:3), inclusive. When sps_num_ver_virtual_boundaries is not present,    it is inferred to be equal to 0.-   sps_virtual_boundary_pos_x_minus1[i] plus 1 specifies the location    of the i-th vertical virtual boundary in units of luma samples    divided by 8. The value of sps_virtual_boundary_pos_x_minus1[i]    shall be in the range of 0 to    Ceil(sps_pic_width_max_in_luma_samples÷8)−2, inclusive.-   sps_num_hor_virtual_boundaries specifies the number of    sps_virtual_boundary_pos_y_minus1 [i] syntax elements that are    present in the SPS. The value of sps_num_hor_virtual_boundaries    shall be in the range of 0 to    (sps_pic_height_max_in_luma_samples<=8? 0: 3), inclusive. When    sps_num_hor_virtual_boundaries is not present, it is inferred to be    equal to 0.

When sps_virtual_boundaries_enabled_flag is equal to 1 andsps_virtual_boundaries_present_flag is equal to 1, the sum ofsps_num_ver_virtual_boundaries and sps_num_hor_virtual_boundaries shallbe greater than 0.

-   sps_virtual_boundary_pos_y_minus1[i] plus 1 specifies the location    of the i-th horizontal virtual boundary in units of luma samples    divided by 8. The value of sps_virtual_boundary_pos_y_minus1[i]    shall be in the range of 0 to    Ceil(sps_pic_height_max_in_luma_samples÷8)−2, inclusive.-   sps_timing_hrd_params_present_flag equal to 1 specifies that the SPS    contains a general_timing_hrd_parameters( ) syntax structure and an    ols_timing_hrd_parameters( ) syntax structure.    sps_timing_hrd_params_present_flag equal to 0 specifies that the SPS    does not contain a general_timing_hrd_parameters( ) syntax structure    or an ols_timing_hrd_parameters( ) syntax structure.-   sps_sublayer_cpb_params_present_flag equal to 1 specifies that the    ols_timing_hrd_parameters( ) syntax structure in the SPS includes    HRD parameters for sublayer representations with TemporalId in the    range of 0 to sps_max_sublayers_minus1, inclusive.    sps_sublayer_cpb_params_present_flag equal to 0 specifies that the    ols_timing_hrd_parameters( ) syntax structure in the SPS includes    HRD parameters for the sublayer representation with TemporalId equal    to sps_max_sublayers_minus1 only. When sps_max_sublayers_minus1 is    equal to 0, the value of sps_sublayer_cpb_params_present_flag is    inferred to be equal to 0.

When sps_sublayer_cpb_params_present_flag is equal to 0, the HRDparameters for the sublayer representations with TemporalId in the rangeof 0 to sps_max_sublayers_minus1−1, inclusive, are inferred to be thesame as that for the sublayer representation with TemporalId equal tosps_max_sublayers_minus1. These include the HRD parameters starting fromthe fixed_pic_rate_general_flag[i] syntax element till thesublayer_hrd_parameters(i) syntax structure immediately under thecondition “if (general_vcl_hrd_params_present_flag)” in theols_timing_hrd_parameters syntax structure.

-   sps_field_seq_flag equal to 1 indicates that the CLVS conveys    pictures that represent fields. sps_field_seq_flag equal to 0    indicates that the CLVS conveys pictures that represent frames.

When sps_field_seq_flag is equal to 1, a frame-field information SEImessage shall be present for every coded picture in the CLVS.

-   -   NOTE—The specified decoding process does not treat pictures that        represent fields or frames differently. A sequence of pictures        that represent fields would therefore be coded with the picture        dimensions of an individual field. For example, pictures that        represent 1080i fields would commonly have cropped output        dimensions of 1920×540, while the sequence picture rate would        commonly express the rate of the source fields (typically        between 50 and 60 Hz), instead of the source frame rate        (typically between 25 and 30 Hz).

-   sps_vui_parameters_present_flag equal to 1 specifies that the syntax    structure vui_payload( ) is present in the SPS RBSP syntax    structure. sps_vui_parameters_present_flag equal to 0 specifies that    the syntax structure vui_payload( ) is not present in the SPS RBSP    syntax structure.

When sps_vui_parameters_present_flag is equal to 0, the informationconveyed in the vui_payload( ) syntax structure is consideredunspecified or determined by the application by external means.

sps_vui_payload_size_minus1 plus 1 specifies the number of RBSP bytes inthe vui_payload( ) syntax structure. The value ofsps_vui_payload_size_minus1 shall be in the range of 0 to 1023,inclusive.

-   -   NOTE—The SPS NAL unit byte sequence containing the vui_payload(        ) syntax structure might include one or more emulation        prevention bytes (represented by emulation_prevention_three_byte        syntax elements). Since the payload size of the vui_payload( )        syntax structure is specified in RBSP bytes, the quantity of        emulation prevention bytes is not included in the size        payloadSize of the vui_payload( ) syntax structure.

-   sps_vui_alignment_zero_bit shall be equal to 0.

-   sps_extension_flag equal to 0 specifies that no    sps_extension_data_flag syntax elements are present in the SPS RBSP    syntax structure. sps_extension_flag equal to 1 specifies that    sps_extension_data_flag syntax elements might be present in the SPS    RBSP syntax structure. sps_extension_flag shall be equal to 0 in    bitstreams conforming to this version of this Specification.    However, some use of sps_extension_flag equal to 1 could be    specified in some future version of this Specification, and decoders    conforming to this version of this Specification shall allow the    value of sps_extension_flag equal to 1 to appear in the syntax.

-   sps_extension_data_flag could have any value. Its presence and value    do not affect the decoding process specified in this version of this    Specification. Decoders conforming to this version of this    Specification shall ignore all sps_extension_data_flag syntax    elements.

As provided above each operating point will conform to a profile, tier,and level, and each of the VPS and SPS may include a profile_tier_level() syntax structure. That is, a VPS or SPS may indicate profile, tier,and level information. Table 5 illustrates the profile_tier_level( )syntax structure provided in JVET-S2001.

TABLE 5 Descriptor profile_tier_level( profileTierPresentFlag,MaxNumSubLayersMinus1 ) {  if( profileTierPresentFlag ) {  general_profile_idc u(7)   general_tier_flag u(1)  } general_level_idc u(8)  ptl_frame_only_constraint_flag u(1) ptl_multilayer_enabled_flag u(1)  if( profileTierPresentFlag )  general_constraints_info( )  for( i = MaxNumSubLayersMinus1 − 1; i >=0; i− − )   ptl_sublayer_level_present_flag[ i ] u(1)  while(!byte_aligned( ) )   ptl_reserved_zero_bit u(1)  for( i =MaxNumSubLayersMinus1 − 1; i >= 0; i− − )   if(ptl_sublayer_level_present_flag[ i ] )    sublayer_level_idc[ i ] u(8) if( profileTierPresentFlag ) {   ptl_num_sub_profiles u(8)   for( i =0; i < ptl_num_sub_profiles; i++ )    general_sub_profile_idc[ i ] u(32)  } }

With respect to Table 5, JVET-S2001 provides the following semantics:

A profile_tier_level( ) syntax structure provides level information and,optionally, profile, tier, sub-profile, and general constraintsinformation to which the OlsInScope conforms.

When the profile_tier_level( ) syntax structure is included in a VPS,the OlsInScope is one or more OLSs specified by the VPS. When theprofile_tier_level( ) syntax structure is included in an SPS, theOlsInScope is the OLS that includes only the layer that is the lowestlayer among the layers that refer to the SPS, and this lowest layer isan independent layer.

-   general_profile_idc indicates a profile to which OlsInScope conforms    as specified in Annex A (of JVET-S2001 and provided below).    Bitstreams shall not contain values of general_profile_idc other    than those specified in Annex A (of JVET-S2001). Other values of    general_profile_idc are reserved for future use by ITU-T I ISO/IEC.    Decoders shall ignore OLSs associated with a reserved value of    general_profile_idc.-   general_tier_flag specifies the tier context for the interpretation    of general_level_idc as specified in Annex A (of JVET-S2001 and    provided below).-   general_level_idc indicates a level to which OlsInScope conforms as    specified in Annex A (of JVET-S2001 and provided below). Bitstreams    shall not contain values of general_level_idc other than those    specified in Annex A (of JVET-S2001). Other values of    general_level_idc are reserved for future use by ITU-T I ISO/IEC.

NOTE—A greater value of general_level_idc indicates a higher level. Themaximum level signalled in the DCI NAL unit for OlsInScope could behigher but not be lower than the level signalled in the SPS for a CLVScontained within OlsInScope.

NOTE—When OlsInScope conforms to multiple profiles, general_profile_idcis expected to indicate the profile that provides the preferred decodedresult or the preferred bitstream identification, as determined by theencoder (in a manner not specified in this Specification).

NOTE—When the CVSs of OlsInScope conform to different profiles, multipleprofile_tier_level( ) syntax structures could be included in the DCI NALunit such that for each CVS of the OlsInScope there is at least one setof indicated profile, tier, and level for a decoder that is capable ofdecoding the CVS.

-   ptl_frame_only_constraint_flag equal to 1 specifies that    sps_field_seq_flag for all pictures in OlsInScope shall be equal    to 0. ptl_frame_only_constraint_flag equal to 0 does not impose such    a constraint.

NOTE—Decoders could ignore the value of ptl_frame_only_constraint_flag,as there are no decoding process requirements associated with it.

-   ptl_multilayer_enabled_flag equal to 1 specifies that the CVSs of    OlsInScope might contain more than one layer.    ptl_multilayer_enabled_flag equal to 0 specifies that all slices in    OlsInScope shall have the same value of nuh_layer_id, i.e., there is    only one layer in the CVSs of OlsInScope.-   ptl_sublayer_level_present_flag[i] equal to 1 specifies that level    information is present in the profile_tier_level( ) syntax structure    for the sublayer representation with TemporalId equal to i.    ptl_sublayer_level_present_flag[i] equal to 0 specifies that level    information is not present in the profile_tier_level( ) syntax    structure for the sublayer representation with TemporalId equal to    i.-   ptl_reserved_zero_bit shall be equal to 0. The value 1 for    ptl_reserved_zero_bit is reserved for future use by ITU-T I ISO/IEC.    Decoders conforming to this version of this Specification shall    ignore the value of ptl_reserved_zero_bit.

The semantics of the syntax element sublayer_level_idc[i] is, apart fromthe specification of the inference of not present values, the same asthe syntax element general_level_idc, but apply to the sublayerrepresentation with TemporalId equal to i.

When not present, the value of sublayer_level_idc[i] is inferred asfollows:

-   -   The value of sublayer_level_idc[MaxNumSubLayersMinusl] is        inferred to be equal to general_level_idc of the same        profile_tier_level( ) structure,    -   For i from MaxNumSubLayersMinusl−1 to 0 (in decreasing order of        values of i), inclusive, sublayer_level_idc[i] is inferred to be        equal to sublayer_level_idc[i+1].

-   ptl_num_sub_profiles specifies the number of the    general_sub_profile_idc[i] syntax elements.

-   general_sub_profile_idc[i] specifies the i-th interoperability    indicator registered as specified by Rec. ITU-T T.35, the contents    of which are not specified in (JVET-S2001).

As described above, when a picture is decoded it is stored to a decodedpicture buffer (DPB) and JVET-S2001 provides where a decoded picturebuffer parameters syntax structure may be include in a VPS or SPS. Table6 illustrates the decoded picture buffer parameters syntax structureprovided in JVET-S2001.

TABLE 6 Descriptor dpb_parameters( MaxSubLayersMinus1, subLayerInfoFlag) {  for( i = ( subLayerInfoFlag ? 0 : MaxSubLayersMinus1 );    i <=MaxSubLayersMinus1; i++ ) {   dpb_max_dec_pic_buffering_minus1[ i ]ue(v)   dpb_max_num_reorder_pics[ i ] ue(v)  dpb_max_latency_increase_plus1[ i ] ue(v)  } }

With respect to Table 6, JVET-S2001 provides the following semantics:

The dpb_parameters( ) syntax structure provides information of DPB size,maximum picture reorder number, and maximum latency for one or more OLSs(output layer sets).

When a dpb_parameters( ) syntax structure is included in a VPS, the OLSsto which the dpb_parameters( ) syntax structure applies are specified bythe VPS. When a dpb_parameters( ) syntax structure is included in anSPS, it applies to the OLS that includes only the layer that is thelowest layer among the layers that refer to the SPS, and this lowestlayer is an independent layer.

-   dpb_max_dec_pic_buffering_minus1[i] plus 1 specifies the maximum    required size of the DPB in units of picture storage buffers when    Htid is equal to i. The value of dpb_max_dec_pic_buffering_minus1    [i] shall be in the range of 0 to MaxDpbSize−1, inclusive, where    MaxDpbSize is as specified below. When i is greater than 0,    dpb_max_dec_pic_buffering_minus1[i] shall be greater than or equal    to dpb_max_dec_pic_buffering_minus1[i−1]. When    dpb_max_dec_pic_buffering_minus1[i] is not present for i in the    range of 0 to MaxSubLayersMinus1−1, inclusive, due to    subLayerInfoFlag being equal to 0, it is inferred to be equal to    dpb_max_dec_pic_buffering_minus1[MaxSubLayersMinus1].-   dpb_max_num_reorder_pics[i] specifies the maximum allowed number of    pictures of the OLS that can precede any picture in the OLS in    decoding order and follow that picture in output order when Htid is    equal to i. The value of dpb_max_num_reorder_pics[i] shall be in the    range of 0 to dpb_max_dec_pic_buffering_minus1 [i], inclusive.

When i is greater than 0, dpb_max_num_reorder_pics[i] shall be greaterthan or equal to dpb_max_num_reorder_pics[i−1]. Whendpb_max_num_reorder_pics[i] is not present for i in the range of 0 toMaxSubLayersMinus1−1, inclusive, due to subLayerInfoFlag being equal to0, it is inferred to be equal todpb_max_num_reorder_pics[MaxSubLayersMinus1].

-   dpb_max_latency_increase_plus1[i] not equal to 0 is used to compute    the value of MaxLatencyPictures[i], which specifies the maximum    number of pictures in the OLS that can precede any picture in the    OLS in output order and follow that picture in decoding order when    Htid is equal to i.

When dpb_max_latency_increase_plus1 [i] is not equal to 0, the value ofMaxLatencyPictures[i] is specified as follows:

-   -   MaxLatencyPictures[i]=dpb_max_num_reorder_pics[i]+dpb_max_latency_increase_plus1[i]−1

When dpb_max_latency_increase_plus1[i] is equal to 0, no correspondinglimit is expressed.

The value of dpb_max_latency_increase_plus1 [i] shall be in the range of0 to 2³²−2, inclusive. When dpb_max_latency_increase_plus1[i] is notpresent for i in the range of 0 to MaxSubLayersMinus1−1, inclusive, dueto subLayerInfoFlag being equal to 0, it is inferred to be equal todpb_max_latency_increase_plus1[MaxSubLayersMinus1].

With respect to profiles, tiers, and levels, JVET-S2001 provides thefollowing in Annex A:

For each operation point identified by TargetOlsIdx and Htid, theprofile, tier, and level information is indicated throughgeneral_profile_idc, general_tier_flag, and sublayer_level_idc[Htid],all found in or derived from the profile_tier_level( ) syntax structurein the VPS that applies to the OLS identified by TargetOlsIdx. When noVPS is available, the profile and tier information is indicated throughgeneral_profile_idc and general_tier_flag in the SPS, and the levelinformation is indicated as follows:

-   -   If Htid is provided by external means indicating the highest        TemporalId of any NAL unit in the bitstream, the level        information is indicated through sublayer_level_idc[Htid] found        in or derived from the SPS.    -   Otherwise (Htid is not provided by external means), the level        information is indicated through general_level_idc in the SPS.

NOTE—Decoders are not required to extract a subset of the bitstream; anysuch extraction process that might be a part of the system is consideredoutside of the scope of the decoding process specified by thisSpecification. The values TargetOlsIdx and Htid are not necessary forthe operation of the decoding process, could be provided by externalmeans, and can be used to check the conformance of the bitstream.

Profiles

Main 10 and Main 10 Still Picture profiles

Bitstreams conforming to the Main 10 or Main 10 Still Picture profileshall obey the following constraints:

-   -   Referenced SPSs shall have ptl_multilayer_enabled_flag equal to        0.    -   In a bitstream conforming to the Main 10 Still Picture profile,        the bitstream shall contain only one picture.    -   Referenced SPSs shall have sps_chroma_format_idc equal to 0 or        1.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   Referenced SPSs shall have sps_palette_enabled_flag equal to 0.    -   In a bitstream conforming to the Main 10 profile,        general_level_idc and sublayer_level_idc[i] for all values of i        in the referenced VPS (when available) and in the referenced        SPSs shall not be equal to 255 (which indicates level 15.5).    -   The tier and level constraints specified for the Main 10 or Main        10 Still Picture profile, as applicable, shall be fulfilled.

Conformance of a bitstream to the Main 10 profile is indicated bygeneral_profile_idc being equal to 1.

Conformance of a bitstream to the Main 10 Still Picture profile isindicated by general_profile_idc being equal to 65.

-   -   NOTE—When the conformance of a bitstream to the Main 10 Still        Picture profile is indicated by general_profile_idc being equal        to 65, and the indicated level is not level 15.5, the conditions        for indication of the conformance of the bitstream to the Main        10 profile are also fulfilled.

Decoders conforming to the Main 10 profile at a specific level of aspecific tier shall be capable of decoding all bitstreams for which allof the following conditions apply:

-   -   The bitstream is indicated to conform to the Main 10 or Main 10        Still Picture profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Decoders conforming to the Main 10 Still Picture profile at a specificlevel of a specific tier shall be capable of decoding all bitstreams forwhich all of the following conditions apply:

-   -   The bitstream is indicated to conform to the Main 10 Still        Picture profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Decoders conforming to the Main 10 Still Picture profile at a specificlevel of a specific tier shall also be capable of decoding of the firstpicture of a bitstream when both of the following conditions apply:

-   -   That bitstream is indicated to conform to the Main 10 profile,        to conform to a tier that is lower than or equal to the        specified tier, and to conform to a level that is not level 15.5        and is lower than or equal to the specified level.    -   That picture is an IRAP picture or is a GDR picture with        ph_recovery_poc_cnt equal to 0, is in an output layer, and has        ph_pic_output_flag equal to 1.

Main 10 4:4:4 and Main 10 4:4:4 Still Picture profiles

Bitstreams conforming to the Main 10 4:4:4 or Main 10 4:4:4 StillPicture profile shall obey the following constraints:

-   -   Referenced SPSs shall have ptl_multilayer_enabled_flag equal to        0.    -   In a bitstream conforming to the Main 10 4:4:4 Still Picture        profile, the bitstream shall contain only one picture.    -   Referenced SPSs shall have sps_chroma_format_idc in the range of        0 to 3, inclusive.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   In a bitstream conforming to the Main 10 4:4:4 profile,        general_level_idc and sublayer_level_idc[i] for all values of i        in the referenced VPS (when available) and in the referenced        SPSs shall not be equal to 255 (which indicates level 15.5).    -   The tier and level constraints specified for the Main 10 4:4:4        or Main 10 4:4:4 Still Picture profile, as applicable, shall be        fulfilled.

Conformance of a bitstream to the Main 10 4:4:4 profile is indicated bygeneral_profile_idc being equal to 33. Conformance of a bitstream to theMain 10 4:4:4 Still Picture profile is indicated by general_profile_idcbeing equal to 97.

-   -   NOTE—When the conformance of a bitstream to the Main 10 4:4:4        Still Picture profile is indicated by general_profile_idc being        equal to 97, and the indicated level is not level 15.5, the        conditions for indication of the conformance of the bitstream to        the Main 10 4:4:4 profile are also fulfilled.

Decoders conforming to the Main 10 4:4:4 profile at a specific level ofa specific tier shall be capable of decoding all bitstreams for whichall of the following conditions apply:

-   -   The bitstream is indicated to conform to the Main 10 4:4:4, Main        10, Main 10 4:4:4 Still Picture, or Main 10 Still Picture        profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Decoders conforming to the Main 10 4:4:4 Still Picture profile at aspecific level of a specific tier shall be capable of decoding allbitstreams for which all of the following conditions apply:

-   -   The bitstream is indicated to conform to the Main 10 4:4:4 Still        Picture or Main 10 Still Picture profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Decoders conforming to the Main 10 4:4:4 Still Picture profile at aspecific level of a specific tier shall also be capable of decoding ofthe first picture of a bitstream when both of the following conditionsapply:

-   -   That bitstream is indicated to conform to the Main 10 4:4:4        profile, to conform to a tier that is lower than or equal to the        specified tier, to conform to a level that is not level 15.5 and        is lower than or equal to the specified level.    -   That picture is an IRAP picture or is a GDR picture with        ph_recovery_poc_cnt equal to 0, is in an output layer, and has        ph_pic_output_flag equal to 1.

Multilayer Main 10 Profile

Bitstreams conforming to the Multilayer Main 10 shall obey the followingconstraints:

-   -   Referenced SPSs shall have sps_chroma_format_idc equal to 0 or        1.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   Referenced SPSs shall have sps_palette_enabled_flag equal to 0.    -   In a bitstream conforming to the Multilayer Main 10 profile,        general_level_idc and sublayer_level_idc[i] for all values of i        in the referenced VPS (when available) and in the referenced        SPSs shall not be equal to 255 (which indicates level 15.5).    -   The tier and level constraints specified for the Multilayer Main        10 profile, as applicable, shall be fulfilled.

Conformance of a bitstream to the Multilayer Main 10 profile isindicated by general_profile_idc being equal to 17.

Decoders conforming to the Multilayer Main 10 profile at a specificlevel of a specific tier shall be capable of decoding all bitstreams forwhich all of the following conditions apply:

-   -   The bitstream is indicated to conform to the Multilayer Main 10,        Main 10, or Main 10 Still Picture profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Multilayer Main 10 4:4:4 profile

Bitstreams conforming to the Multilayer Main 10 4:4:4 profile shall obeythe following constraints:

-   -   Referenced SPSs shall have sps_chroma_format_idc in the range of        0 to 3, inclusive.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   In a bitstream conforming to the Multilayer Main 10 4:4:4        profile, general_level_idc and sublayer_level_idc[i] for all        values of i in the referenced VPS (when available) and in the        referenced SPSs shall not be equal to 255 (which indicates level        15.5).    -   The tier and level constraints specified for the Multilayer Main        10 4:4:4 profile, as applicable, shall be fulfilled.

Conformance of a bitstream to the Multilayer Main 10 4:4:4 profile isindicated by general_profile_idc being equal to 49.

Decoders conforming to the Multilayer Main 10 4:4:4 profile at aspecific level of a specific tier shall be capable of decoding allbitstreams for which all of the following conditions apply:

-   -   The bitstream is indicated to conform to the Multilayer Main 10        4:4:4, Multilayer Main 10, Main 10 4:4:4, Main 10, Main 10 4:4:4        Still Picture, or Main 10 Still Picture profile.    -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

General Tier and Level Limits

For purposes of comparison of tier capabilities, the tier withgeneral_tier_flag equal to 0 (i.e., the Main tier) is considered to be alower tier than the tier with general_tier_flag equal to 1 (i.e., theHigh tier). For purposes of comparison of level capabilities, aparticular level of a specific tier is considered to be a lower levelthan some other level of the same tier when the value of thegeneral_level_idc or sublayer_level_idc[i] of the particular level isless than that of the other level.

The following is specified for expressing the constraints in this annex:

-   -   Let AU n be the n-th AU in decoding order, with the first AU        being AU 0 (i.e., the 0-th AU).    -   For an OLS with OLS index TargetOlsIdx, the variables        PicWidthMaxInSamplesY, PicHeightMaxInSamplesY, and        PicSizeMaxInSamplesY, and the applicable dpb_parameters( )        syntax structure are derived as follows:    -   If NumLayersInOls[TargetOlsIdx] is equal to 1,        PicWidthMaxInSamplesY is set equal to        sps_pic_width_max_in_luma_samples, PicHeightMaxInSamplesY is set        equal to sps_pic_height_max_in_luma_samples, and        PicSizeMaxInSamplesY is set equal to        PicWidthMaxInSamplesY*PicHeightMaxInSamplesY, where        sps_pic_width_max_in_luma_samples and        sps_pic_height_max_in_luma_samples are found in the SPS referred        to by the layer in the OLS, and the applicable dpb_parameters( )        syntax structure is also found in that SPS.    -   Otherwise (NumLayersInOls[TargetOlsIdx] is greater than 1),        PicWidthMaxInSamplesY is set equal to        vps_ols_dpb_pic_width[MultiLayerOlsIdx[TargetOlsIdx] ],        PicHeightMaxInSamplesY is set equal to        vps_ols_dpb_pic_height[MultiLayerOlsIdx[TargetOlsIdx] ],        PicSizeMaxInSamplesY is set equal to        PicWidthMaxInSamplesY*PicHeightMaxInSamplesY, and the applicable        dpb_parameters( ) syntax structure is identified by        vps_ols_dpb_params_idx[MultiLayerOlsIdx[TargetOlsIdx] ] found in        the VPS.

Table 7 specifies the limits for each level of each tier for levelsother than level 15.5.

When the specified level is not level 15.5, bitstreams conforming to aprofile at a specified tier and level shall obey the followingconstraints for each bitstream conformance test as specified:

-   -   a) PicSizeMaxInSamplesY shall be less than or equal to        MaxLumaPs, where MaxLumaPs is specified in Table 7.    -   b) The value of PicWidthMaxInSamplesY shall be less than or        equal to Sqrt(MaxLumaPs*8).    -   c) The value of PicHeightMaxInSamplesY shall be less than or        equal to Sqrt(MaxLumaPs*8).    -   d) For each referenced PPS, the value of NumTileColumns shall be        less than or equal to MaxTileCols and the value of NumTilesInPic        shall be less than or equal to MaxTilesPerAu, where MaxTileCols        and MaxTilesPerAu are specified in Table 7.    -   e) For each referenced PPS, the value of ColWidthVal[i]        *CtbSizeY, for each i in the range of 0 to NumTileColumns−1,        inclusive, shall be less than or equal to 0.5        Sqrt(Max(level4Val, MaxLumaPs)*8), where MaxLumaPs is specified        in Table 7 and level4Val is equal to 2 228 224.        -   NOTE—The maximum tile width in luma samples is also less            than or equal to the picture width, which is less than or            equal to Sqrt(MaxLumaPs*8).    -   f) For the VCL HRD parameters, CpbSize[Htid][i] shall be less        than or equal to CpbVclFactor*MaxCPB for at least one value of i        in the range of 0 to hrd_cpb_cnt_minus1, inclusive, where        CpbSize[Htid][i] is specified based on parameters selected,        CpbVclFactor is specified in Table 9 and MaxCPB is specified in        Table 7 in units of CpbVclFactor bits.    -   g) For the NAL HRD parameters, CpbSize[Htid][i] shall be less        than or equal to CpbNalFactor*MaxCPB for at least one value of i        in the range of 0 to hrd_cpb_cnt_minus1, inclusive, where        CpbSize[Htid][i] is specified based on parameters selected,        CpbNalFactor is specified in Table 9, and MaxCPB is specified in        Table 7 in units of CpbNalFactor bits.

A tier and level to which a bitstream conforms are indicated by thesyntax elements general_tier_flag and general_level_idc, and a level towhich a sublayer representation conforms are indicated by the syntaxelement sublayer_level_idc[i], as follows:

-   -   If the specified level is not level 15.5, general_tier_flag        equal to 0 indicates conformance to the Main tier,        general_tier_flag equal to 1 indicates conformance to the High        tier, according to the tier constraints specified in Table 7 and        general_tier_flag shall be equal to 0 for levels below level 4        (corresponding to the entries in Table 7 marked with “−”).        Otherwise (the specified level is level 15.5), it is a        requirement of bitstream conformance that general_tier_flag        shall be equal to 1 and the value 0 for general_tier_flag is        reserved for future use by ITU-T I ISO/IEC and decoders shall        ignore the value of general_tier_flag.    -   general_level_idc and sublayer_level_idc[i] shall be set equal        to a value of general_level_idc for the level number specified        in Table 7.

TABLE 7 Max CPB size MaxCPB (CpbVclFactor or CpbNalFactorbits) Max # ofMax # of general_level_ Max luma picture size Main High Max slices perpicture tile rows tile columns Level idc_value* MaxLumaPs (samples) tiertier MaxSlicesPerPicture MaxTileRows MaxTileCols 1 16 36 864 350 — 16 11 2 32 122 880 1 500 — 16 1 1 2.1 35 245 760 3 000 — 20 1 1 3 48 552 9606 000 — 30 4 2 3.1 51 983 040 10 000 — 40 9 3 4 64 2 228 224 12 000 30000 75 25 5 4.1 67 2 228 224 20 000 50 000 75 25 5 5 80 8 912 896 25 000100 000 200 110 10 5.1 83 8 912 896 40 000 160 000 200 110 10 5.2 86 8912 896 60 000 240 000 200 110 10 6 96 35 651 584 60 000 240 000 600 44020 6.1 99 35 651 584 120 000 480 000 600 440 20 6.2 102 35 651 584 180000 800 000 600 440 20 *The level numbers in this table are in the formof “majorNum.minorNum”, and the value of general_level_idc for each ofthe levels is equal to majorNum * 16 + minorNum * 3.

Profile-Specific Level Limits

The following is specified for expressing the constraints in this annex:

-   -   Let the variable FrVal be set equal to 1÷300 if        general_tier_flag is equal to 0 and set equal to 1÷960        otherwise.

The variable HbrFactor is defined as follows:

-   -   If the bitstream is indicated to conform to the Main 10, Main 10        4:4:4, Multilayer Main 10, or Multilayer Main 10 4:4:4 profile,        HbrFactor is set equal to 1.

The variable BrVclFactor, which represents the VCL bit rate scalefactor, is set equal to CpbVclFactor*HbrFactor. The variableBrNalFactor, which represents the NAL bit rate scale factor, is setequal to CpbNalFactor*HbrFactor. The variable MinCr is set equal toMinCrBase*MinCrScaleFactor HbrFactor.

When the specified level is not level 15.5, the value ofdpb_max_dec_pic_buffering_minus1 [Htid]+1 shall be less than or equal toMaxDpbSize, which is derived as follows:

-   -   if (2*PicSizeMaxInSamplesY<=MaxLumaPs)        -   MaxDpbSize=2*maxDpbPicBuf    -   else if (3*PicSizeMaxInSamplesY<=2*MaxLumaPs)        -   MaxDpbSize=3*maxDpbPicBuf/2    -   else        -   MaxDpbSize=maxDpbPicBuf            where MaxLumaPs is specified in Table 7, maxDpbPicBuf is            equal to 8, and dpb_max_dec_pic_buffering_minus1[Htid] is            found in or derived from the applicable dpb_parameters( )            syntax structure.

Let numDecPics be the number of pictures in AU n. The variableAuSizeMaxInSamplesY[n] is set equal to PicSizeMaxInSamplesY*numDecPics.

Bitstreams conforming to the Main 10, Main 10 4:4:4, Multilayer Main 10,or Multilayer Main 10 4:4:4 profile at a specified tier and level shallobey the following constraints for each bitstream conformance test:

-   -   a) The nominal removal time of AU n (with n greater than 0) from        the CPB, as specified, shall satisfy the constraint that        AuNominalRemovalTime[n]−AuCpbRemovalTime[n−1] is greater than or        equal to Max(AuSizeMaxInSamplesY[n−1]÷MaxLumaSr, FrVal), where        MaxLumaSr is the value specified in Table 8 that applies to AU        n−1.    -   b) The difference between consecutive output times of pictures        of different AUs from the DPB, as specified, shall satisfy the        constraint that DpbOutputInterval[n] is greater than or equal to        Max(AuSizeMaxInSamplesY[n]÷MaxLumaSr, FrVal), where MaxLumaSr is        the value specified in Table 8 for AU n, provided that AU n has        a picture that is output and AU n is not the last AU of the        bitstream that has a picture that is output.    -   c) The removal time of AU 0 shall satisfy the constraint that        the number of slices in AU 0 is less than or equal to Min(Max(1,        MaxSlicesPerAu*MaxLumaSr/MaxLumaPs*(AuCpbRemovalTime[0]−AuNominalRemovalTime[0])+MaxSlicesPerAu*AuSizeMaxInSamplesY[0]/MaxLumaPs),        MaxSlicesPerAu), where MaxSlicesPerAu, MaxLumaPs and MaxLumaSr        are the values specified in Table 7 and Table 8, respectively,        that apply to AU 0.    -   d) The difference between consecutive CPB removal times of AUs n        and n−1 (with n greater than 0) shall satisfy the constraint        that the number of slices in AU n is less than or equal to        Min((Max(1,        MaxSlicesPerAu*MaxLumaSr/MaxLumaPs*(AuCpbRemovalTime[n]−AuCpbRemovalTime[n]−1)),        MaxSlicesPerAu), where MaxSlicesPerAu, MaxLumaPs, and MaxLumaSr        are the values specified in Table 7 and Table 8 that apply to AU        n.    -   e) For the VCL HRD parameters, BitRate[Htid][i] shall be less        than or equal to BrVclFactor*MaxBR for at least one value of i        in the range of 0 to hrd_cpb_cnt_minus1, inclusive, where        BitRate[Htid][i] is specified based on parameters selected as        specified and MaxBR is specified in Table 8 in units of        BrVclFactor bits/s.    -   f) For the NAL HRD parameters, BitRate[Htid][i] shall be less        than or equal to BrNalFactor*MaxBR for at least one value of i        in the range of 0 to hrd_cpb_cnt_minus1, inclusive, where        BitRate[Htid][i] is specified based on parameters selected as        specified and MaxBR is specified in Table 8 in units of        BrNalFactor bits/s.    -   g) The sum of the NumByteslnNalUnit variables for AU 0 shall be        less than or equal to        FormatCapabilityFactor*(Max(AuSizeMaxInSamplesY[0],        FrVal*MaxLumaSr)+MaxLumaSr*(AuCpbRemovalTime[0]−AuNominalRemovalTime[0]))÷MinCr,        where MaxLumaSr and FormatCapabilityFactor are the values        specified in Table 7 and Table 8, respectively, that apply to AU        0.    -   h) The sum of the NumByteslnNalUnit variables for AU n (with n        greater than 0) shall be less than or equal to        FormatCapabilityFactor*MaxLumaSr*(AuCpbRemovalTime[n]−AuCpbRemovalTime[n−1])÷MinCr,        where MaxLumaSr and FormatCapabilityFactor are the values        specified in Table 7 and Table 8 respectively, that apply to AU        n.    -   i) The removal time of AU 0 shall satisfy the constraint that        the number of tiles in AU 0 is less than or equal to Min(Max(1,        MaxTilesPerAu*120*(AuCpbRemovalTime[0]−AuNominalRemovalTime[0])+MaxTilesPerAu*AuSizeMaxInSamplesY[0]/MaxLumaPs),        MaxTilesPerAu), where MaxTilesPerAu is the value specified in        Table 7 that applies to AU 0.    -   j) The difference between consecutive CPB removal times of AUs n        and n−1 (with n greater than 0) shall satisfy the constraint        that the number of tiles in AU n is less than or equal to        Min(Max(1,        MaxTilesPerAu*120*(AuCpbRemovalTime[n]−AuCpbRemovalTime[n−1])),        MaxTilesPerAu), where MaxTilesPerAu is the value specified in        Table 7 that apply to AU n.

TABLE 8 Max bit rate MaxBR Max luma sample rate (BrVclFactor or Mincompression MaxLumaSr BrNalFactor bits/s) ratio MinCrBase Level(samples/sec) Main tier High tier Main tier High tier 1.0     552 960    128 — 2 2 2.0     3 686 400  1 500 — 2 2 2.1     7 372 800  3 000 —2 2 3.0    16 588 800  6 000 — 2 2 3.1    33 177 600  10 000 — 2 2 4.0   66 846 720  12 000  30 000 4 4 4.1    133 693 440  20 000  50 000 4 45.0    267 386 880  25 000 100 000 6 4 5.1    534 773 760  40 000 160000 8 4 5.2 1 069 547 520  60 000 240 000 8 4 6.0 1 069 547 520  60 000240 000 8 4 6.1 2 139 095 040 120 000 480 000 8 4 6.2 4 278 190 080 240000 800 000 8 4

TABLE 9 Profile CpbVclFactor CpbNalFactor FormatCapabilityFactorMinCrScaleFactor Main 10, Main 10 Still Picture, 1 000 1 100 1.875 1.0Multilayer Main 10 Main 10 4:4:4, Main 10 4:4:4 Still 2 500 2 750 3.7500.5 Picture, Multilayer Main 10 4:4:4

It should be noted that the profile and level definitions provided inJVET-S2001 are inadequate to support multilayer 8K (i.e., e.g., pictureresolutions of 7680×4320) applications. For example, in JVET-S2001 noneof the defined levels can support a two-layer bitstream, where thehighest layer is 8K and both layers use a typical random access codingstructure, such as those defined in common test conditions. That is, atwo-layer stream, where the higher layer is 8K and both layers use atypical random access coding structure, requires a relatively large DPBand in JVET-S2001, the highest level (6.2) cannot accommodate a DPBlarger than 8 pictures at 8K resolution. It should be noted that, forexample, the configuration used for common test conditions requires aDPB of size 6 (dpb_max_dec_pic_buffering_minus1 is set to 5). With twolayers, the required DPB size is 12. According to the techniques herein,profiles and levels and corresponding signaling are provided to provideadequate support for multilayer 8K applications.

FIG. 1 is a block diagram illustrating an example of a system that maybe configured to code (i.e., encode and/or decode) video data accordingto one or more techniques of this disclosure. System 100 represents anexample of a system that may encapsulate video data according to one ormore techniques of this disclosure. As illustrated in FIG. 1, system 100includes source device 102, communications medium 110, and destinationdevice 120. In the example illustrated in FIG. 1, source device 102 mayinclude any device configured to encode video data and transmit encodedvideo data to communications medium 110. Destination device 120 mayinclude any device configured to receive encoded video data viacommunications medium 110 and to decode encoded video data. Sourcedevice 102 and/or destination device 120 may include computing devicesequipped for wired and/or wireless communications and may include, forexample, set top boxes, digital video recorders, televisions, desktop,laptop or tablet computers, gaming consoles, medical imagining devices,and mobile devices, including, for example, smartphones, cellulartelephones, personal gaming devices.

Communications medium 110 may include any combination of wireless andwired communication media, and/or storage devices. Communications medium110 may include coaxial cables, fiber optic cables, twisted pair cables,wireless transmitters and receivers, routers, switches, repeaters, basestations, or any other equipment that may be useful to facilitatecommunications between various devices and sites. Communications medium110 may include one or more networks. For example, communications medium110 may include a network configured to enable access to the World WideWeb, for example, the Internet. A network may operate according to acombination of one or more telecommunication protocols.Telecommunications protocols may include proprietary aspects and/or mayinclude standardized telecommunication protocols. Examples ofstandardized telecommunications protocols include Digital VideoBroadcasting (DVB) standards, Advanced Television Systems Committee(ATSC) standards, Integrated Services Digital Broadcasting (ISDB)standards, Data Over Cable Service Interface Specification (DOCSIS)standards, Global System Mobile Communications (GSM) standards, codedivision multiple access (CDMA) standards, 3rd Generation PartnershipProject (3GPP) standards, European Telecommunications StandardsInstitute (ETSI) standards, Internet Protocol (IP) standards, WirelessApplication Protocol (WAP) standards, and Institute of Electrical andElectronics Engineers (IEEE) standards.

Storage devices may include any type of device or storage medium capableof storing data. A storage medium may include a tangible ornon-transitory computer-readable media. A computer readable medium mayinclude optical discs, flash memory, magnetic memory, or any othersuitable digital storage media. In some examples, a memory device orportions thereof may be described as non-volatile memory and in otherexamples portions of memory devices may be described as volatile memory.Examples of volatile memories may include random access memories (RAM),dynamic random access memories (DRAM), and static random access memories(SRAM). Examples of non-volatile memories may include magnetic harddiscs, optical discs, floppy discs, flash memories, or forms ofelectrically programmable memories (EPROM) or electrically erasable andprogrammable (EEPROM) memories. Storage device(s) may include memorycards (e.g., a Secure Digital (SD) memory card), internal/external harddisk drives, and/or internal/external solid state drives. Data may bestored on a storage device according to a defined file format.

FIG. 4 is a conceptual drawing illustrating an example of componentsthat may be included in an implementation of system 100. In the exampleimplementation illustrated in FIG. 4, system 100 includes one or morecomputing devices 402A-402N, television service network 404, televisionservice provider site 406, wide area network 408, local area network410, and one or more content provider sites 412A-412N. Theimplementation illustrated in FIG. 4 represents an example of a systemthat may be configured to allow digital media content, such as, forexample, a movie, a live sporting event, etc., and data and applicationsand media presentations associated therewith to be distributed to andaccessed by a plurality of computing devices, such as computing devices402A-402N. In the example illustrated in FIG. 4, computing devices402A-402N may include any device configured to receive data from one ormore of television service network 404, wide area network 408, and/orlocal area network 410. For example, computing devices 402A-402N may beequipped for wired and/or wireless communications and may be configuredto receive services through one or more data channels and may includetelevisions, including so-called smart televisions, set top boxes, anddigital video recorders. Further, computing devices 402A-402N mayinclude desktop, laptop, or tablet computers, gaming consoles, mobiledevices, including, for example, “smart” phones, cellular telephones,and personal gaming devices.

Television service network 404 is an example of a network configured toenable digital media content, which may include television services, tobe distributed. For example, television service network 404 may includepublic over-the-air television networks, public or subscription-basedsatellite television service provider networks, and public orsubscription-based cable television provider networks and/or over thetop or Internet service providers. It should be noted that although insome examples television service network 404 may primarily be used toenable television services to be provided, television service network404 may also enable other types of data and services to be providedaccording to any combination of the telecommunication protocolsdescribed herein. Further, it should be noted that in some examples,television service network 404 may enable two-way communications betweentelevision service provider site 406 and one or more of computingdevices 402A-402N. Television service network 404 may comprise anycombination of wireless and/or wired communication media. Televisionservice network 404 may include coaxial cables, fiber optic cables,twisted pair cables, wireless transmitters and receivers, routers,switches, repeaters, base stations, or any other equipment that may beuseful to facilitate communications between various devices and sites.Television service network 404 may operate according to a combination ofone or more telecommunication protocols. Telecommunications protocolsmay include proprietary aspects and/or may include standardizedtelecommunication protocols. Examples of standardized telecommunicationsprotocols include DVB standards, ATSC standards, ISDB standards, DTMBstandards, DMB standards, Data Over Cable Service InterfaceSpecification (DOCSIS) standards, HbbTV standards, W3C standards, andUPnP standards.

Referring again to FIG. 4, television service provider site 406 may beconfigured to distribute television service via television servicenetwork 404. For example, television service provider site 406 mayinclude one or more broadcast stations, a cable television provider, ora satellite television provider, or an Internet-based televisionprovider. For example, television service provider site 406 may beconfigured to receive a transmission including television programmingthrough a satellite uplink/downlink. Further, as illustrated in FIG. 4,television service provider site 406 may be in communication with widearea network 408 and may be configured to receive data from contentprovider sites 412A-412N. It should be noted that in some examples,television service provider site 406 may include a television studio andcontent may originate therefrom.

Wide area network 408 may include a packet based network and operateaccording to a combination of one or more telecommunication protocols.Telecommunications protocols may include proprietary aspects and/or mayinclude standardized telecommunication protocols. Examples ofstandardized telecommunications protocols include Global System MobileCommunications (GSM) standards, code division multiple access (CDMA)standards, 3rd Generation Partnership Project (3GPP) standards, EuropeanTelecommunications Standards Institute (ETSI) standards, Europeanstandards (EN), IP standards, Wireless Application Protocol (WAP)standards, and Institute of Electrical and Electronics Engineers (IEEE)standards, such as, for example, one or more of the IEEE 802 standards(e.g., Wi-Fi). Wide area network 408 may comprise any combination ofwireless and/or wired communication media. Wide area network 408 mayinclude coaxial cables, fiber optic cables, twisted pair cables,Ethernet cables, wireless transmitters and receivers, routers, switches,repeaters, base stations, or any other equipment that may be useful tofacilitate communications between various devices and sites. In oneexample, wide area network 408 may include the Internet. Local areanetwork 410 may include a packet based network and operate according toa combination of one or more telecommunication protocols. Local areanetwork 410 may be distinguished from wide area network 408 based onlevels of access and/or physical infrastructure. For example, local areanetwork 410 may include a secure home network.

Referring again to FIG. 4, content provider sites 412A-412N representexamples of sites that may provide multimedia content to televisionservice provider site 406 and/or computing devices 402A-402N. Forexample, a content provider site may include a studio having one or morestudio content servers configured to provide multimedia files and/orstreams to television service provider site 406. In one example, contentprovider sites 412A-412N may be configured to provide multimedia contentusing the IP suite. For example, a content provider site may beconfigured to provide multimedia content to a receiver device accordingto Real Time Streaming Protocol (RTSP), HTTP, or the like. Further,content provider sites 412A-412N may be configured to provide data,including hypertext based content, and the like, to one or more ofreceiver devices computing devices 402A-402N and/or television serviceprovider site 406 through wide area network 408. Content provider sites412A-412N may include one or more web servers. Data provided by dataprovider site 412A-412N may be defined according to data formats.

Referring again to FIG. 1, source device 102 includes video source 104,video encoder 106, data encapsulator 107, and interface 108. Videosource 104 may include any device configured to capture and/or storevideo data. For example, video source 104 may include a video camera anda storage device operably coupled thereto. Video encoder 106 may includeany device configured to receive video data and generate a compliantbitstream representing the video data. A compliant bitstream may referto a bitstream that a video decoder can receive and reproduce video datatherefrom. Aspects of a compliant bitstream may be defined according toa video coding standard. When generating a compliant bitstream videoencoder 106 may compress video data. Compression may be lossy(discernible or indiscernible to a viewer) or lossless. FIG. 5 is ablock diagram illustrating an example of video encoder 500 that mayimplement the techniques for encoding video data described herein. Itshould be noted that although example video encoder 500 is illustratedas having distinct functional blocks, such an illustration is fordescriptive purposes and does not limit video encoder 500 and/orsub-components thereof to a particular hardware or softwarearchitecture. Functions of video encoder 500 may be realized using anycombination of hardware, firmware, and/or software implementations.

Video encoder 500 may perform intra prediction coding and interprediction coding of picture areas, and, as such, may be referred to asa hybrid video encoder. In the example illustrated in FIG. 5, videoencoder 500 receives source video blocks. In some examples, source videoblocks may include areas of picture that has been divided according to acoding structure. For example, source video data may includemacroblocks, CTUs, CBs, sub-divisions thereof, and/or another equivalentcoding unit. In some examples, video encoder 500 may be configured toperform additional sub-divisions of source video blocks. It should benoted that the techniques described herein are generally applicable tovideo coding, regardless of how source video data is partitioned priorto and/or during encoding. In the example illustrated in FIG. 5, videoencoder 500 includes summer 502, transform coefficient generator 504,coefficient quantization unit 506, inverse quantization and transformcoefficient processing unit 508, summer 510, intra prediction processingunit 512, inter prediction processing unit 514, filter unit 516, andentropy encoding unit 518. As illustrated in FIG. 5, video encoder 500receives source video blocks and outputs a bitstream.

In the example illustrated in FIG. 5, video encoder 500 may generateresidual data by subtracting a predictive video block from a sourcevideo block. The selection of a predictive video block is described indetail below. Summer 502 represents a component configured to performthis subtraction operation. In one example, the subtraction of videoblocks occurs in the pixel domain. Transform coefficient generator 504applies a transform, such as a discrete cosine transform (DCT), adiscrete sine transform (DST), or a conceptually similar transform, tothe residual block or sub-divisions thereof (e.g., four 8×8 transformsmay be applied to a 16×16 array of residual values) to produce a set ofresidual transform coefficients. Transform coefficient generator 504 maybe configured to perform any and all combinations of the transformsincluded in the family of discrete trigonometric transforms, includingapproximations thereof. Transform coefficient generator 504 may outputtransform coefficients to coefficient quantization unit 506. Coefficientquantization unit 506 may be configured to perform quantization of thetransform coefficients. The quantization process may reduce the bitdepth associated with some or all of the coefficients. The degree ofquantization may alter the rate-distortion (i.e., bit-rate vs. qualityof video) of encoded video data. The degree of quantization may bemodified by adjusting a quantization parameter (QP). A quantizationparameter may be determined based on slice level values and/or CU levelvalues (e.g., CU delta QP values). QP data may include any data used todetermine a QP for quantizing a particular set of transformcoefficients. As illustrated in FIG. 5, quantized transform coefficients(which may be referred to as level values) are output to inversequantization and transform coefficient processing unit 508. Inversequantization and transform coefficient processing unit 508 may beconfigured to apply an inverse quantization and an inversetransformation to generate reconstructed residual data. As illustratedin FIG. 5, at summer 510, reconstructed residual data may be added to apredictive video block. In this manner, an encoded video block may bereconstructed and the resulting reconstructed video block may be used toevaluate the encoding quality for a given prediction, transformation,and/or quantization. Video encoder 500 may be configured to performmultiple coding passes (e.g., perform encoding while varying one or moreof a prediction, transformation parameters, and quantizationparameters). The rate-distortion of a bitstream or other systemparameters may be optimized based on evaluation of reconstructed videoblocks. Further, reconstructed video blocks may be stored and used asreference for predicting subsequent blocks.

Referring again to FIG. 5, intra prediction processing unit 512 may beconfigured to select an intra prediction mode for a video block to becoded. Intra prediction processing unit 512 may be configured toevaluate a frame and determine an intra prediction mode to use to encodea current block. As described above, possible intra prediction modes mayinclude planar prediction modes, DC prediction modes, and angularprediction modes. Further, it should be noted that in some examples, aprediction mode for a chroma component may be inferred from a predictionmode for a luma prediction mode. Intra prediction processing unit 512may select an intra prediction mode after performing one or more codingpasses. Further, in one example, intra prediction processing unit 512may select a prediction mode based on a rate-distortion analysis. Asillustrated in FIG. 5, intra prediction processing unit 512 outputsintra prediction data (e.g., syntax elements) to entropy encoding unit518 and transform coefficient generator 504. As described above, atransform performed on residual data may be mode dependent (e.g., asecondary transform matrix may be determined based on a predictionmode).

Referring again to FIG. 5, inter prediction processing unit 514 may beconfigured to perform inter prediction coding for a current video block.Inter prediction processing unit 514 may be configured to receive sourcevideo blocks and calculate a motion vector for PUs of a video block. Amotion vector may indicate the displacement of a prediction unit of avideo block within a current video frame relative to a predictive blockwithin a reference frame. Inter prediction coding may use one or morereference pictures. Further, motion prediction may be uni-predictive(use one motion vector) or bi-predictive (use two motion vectors). Interprediction processing unit 514 may be configured to select a predictiveblock by calculating a pixel difference determined by, for example, sumof absolute difference (SAD), sum of square difference (SSD), or otherdifference metrics. As described above, a motion vector may bedetermined and specified according to motion vector prediction. Interprediction processing unit 514 may be configured to perform motionvector prediction, as described above. Inter prediction processing unit514 may be configured to generate a predictive block using the motionprediction data. For example, inter prediction processing unit 514 maylocate a predictive video block within a frame buffer (not shown in FIG.5). It should be noted that inter prediction processing unit 514 mayfurther be configured to apply one or more interpolation filters to areconstructed residual block to calculate sub-integer pixel values foruse in motion estimation. Inter prediction processing unit 514 mayoutput motion prediction data for a calculated motion vector to entropyencoding unit 518.

Referring again to FIG. 5, filter unit 516 receives reconstructed videoblocks and coding parameters and outputs modified reconstructed videodata. Filter unit 516 may be configured to perform deblocking and/orSample Adaptive Offset (SAO) filtering. SAO filtering is a non-linearamplitude mapping that may be used to improve reconstruction by addingan offset to reconstructed video data. It should be noted that asillustrated in FIG. 5, intra prediction processing unit 512 and interprediction processing unit 514 may receive modified reconstructed videoblock via filter unit 216. Entropy encoding unit 518 receives quantizedtransform coefficients and predictive syntax data (i.e., intraprediction data and motion prediction data). It should be noted that insome examples, coefficient quantization unit 506 may perform a scan of amatrix including quantized transform coefficients before thecoefficients are output to entropy encoding unit 518. In other examples,entropy encoding unit 518 may perform a scan. Entropy encoding unit 518may be configured to perform entropy encoding according to one or moreof the techniques described herein. In this manner, video encoder 500represents an example of a device configured to generate encoded videodata according to one or more techniques of this disclosure.

Referring again to FIG. 1, data encapsulator 107 may receive encodedvideo data and generate a compliant bitstream, e.g., a sequence of NALunits according to a defined data structure. A device receiving acompliant bitstream can reproduce video data therefrom. Further, asdescribed above, sub-bitstream extraction may refer to a process where adevice receiving a compliant bitstream forms a new compliant bitstreamby discarding and/or modifying data in the received bitstream. It shouldbe noted that the term conforming bitstream may be used in place of theterm compliant bitstream. In one example, data encapsulator 107 may beconfigured to generate syntax according to one or more techniquesdescribed herein. It should be noted that data encapsulator 107 need notnecessary be located in the same physical device as video encoder 106.For example, functions described as being performed by video encoder 106and data encapsulator 107 may be distributed among devices illustratedin FIG. 4.

As described above, the definitions and signaling of profile and levelinformation in JVET-S2001 may be less than ideal. In one example,according to the techniques herein, the variable maxDpbPicBuf, may bedefined to be equal to 16 for the existing multilayer profiles and thederivation of MaxDpbSize may be as follows:

if (2*PicSizeMaxInSamplesY<=MaxLumaPs)

MaxDpbSize=2*maxDpbPicBuf else if (3*PicSizeMaxInSamplesY<=2*MaxLumaPs)

MaxDpbSize=3*maxDpbPicBuf/2 else

MaxDpbSize=maxDpbPicBuf where MaxLumaPs is specified in Table 7,maxDpbPicBuf is equal to 16 if the bitstream is indicated to conform tothe Multilayer Main 10 or Multilayer Main 10 4:4:4 profile and equal to8 otherwise, and dpb_max_dec_pic_buffering_minus1[Htid] is found in orderived from the applicable dpb_parameters( ) syntax structure.

In another example, maxDpbPicBuf can be defined to be equal to 32 forthe multilayer profiles, such as to support more than two layers at themaximum resolution defined by each level. It should be noted that theincrease of maxDpbPicBuf can result in larger values of maxDpbSize,meaning that a decoder would have to manage a larger number of picturesin the decoded picture buffer. If so desired, this can be mitigated byintroducing a cap on the value of maxDpbSize. For example, in oneexample, the derivation of maxDpbSize may be as follows:

if (2*PicSizeMaxInSamplesY<=MaxLumaPs)

MaxDpbSize=Min(2*maxDpbPicBuf, maxDpbSizeLimit) else if(3*PicSizeMaxInSamplesY<=2*MaxLumaPs)

MaxDpbSize=Min (3*maxDpbPicBuf/2, maxDpbSizeLimit) else

MaxDpbSize=maxDpbPicBuf where maxDpbSizeLimit can be set equal to 16 (oranother value that is larger than or equal to maxDpbPicBuf).

In one example, according to the techniques herein, a level 7 thatsupports 16K (i.e., e.g., 15360×8640) resolution at 30 Hz may be definedand a corresponding general_level_idc value may be signaled. It shouldbe noted that given the pixel per second rate, such a level would alsosupport 8K resolution at 120 Hz and the value of MaxDpbSize would be 16for 8K content. Further, in one example, according to the techniquesherein, a level 6.3 that supports 12K resolution (e.g., 11520×6480) at60 Hz may be defined and a corresponding general_level_idc value may besignaled. It should be noted that given the pixel per second rate, sucha level would also support 8K resolution at 120 Hz and the value ofMaxDpbSize would be 16 for 8K content. That is, according to thetechniques herein, Tables 7 and 8 may be appended with one or both ofthe entries in respective Tables 10 and 11 below.

TABLE 10 Max CPB size MaxCPB (CpbVclFactor or CpbNalFactor Max # of Max# of general_level_ Max luma picture size bits) Max slices per picturetile rows tile columns Level idc_value* MaxLumaPs (samples) Main tierHigh tier MaxSlicesPerPicture MaxTileRows MaxTileCols 6.3 105 80 216 064240 000 800 000 1000 990 30 7.0 112 142 606 336 240 000 800 000 18001760 40

TABLE 11 Max bit rate MaxBR Max luma sample rate (BrVclFactor or Mincompression MaxLumaSr BrNalFactor bits/s) ratio MinCrBase Level(samples/sec) Main tier High tier Main tier High tier 6.3 4 812 963 840320 000 800 000 8 4 7.0 4 278 190 080 240 000 800 000 8 4

In one example, according to the techniques herein, multilayer profiles,Multilayer Extended Memory 10 and Multilayer Extended Memory 10 4:4:4may be defined, and general_profile_idc values may be assigned to them.In example, the assigned values may be 18 and 50. Alternatively, in oneexample, values 25 and 57 may be used. It should be noted that in such acase, the bit of weight 8 in general_profile_idc can be interpreted tosignal extended reference memory. In one example, Multilayer ExtendedMemory 10 and Multilayer Extended Memory 10 4:4:4 may be respectivelydefined as follows with the Multilayer Main 10 properties in Table 9applicable to Multilayer Extended Memory 10 and the Multilayer Main 104:4:4 properties in Table 9 applicable to Multilayer Extended Memory 104:4:4:

Multilayer Extended Memory 10 Profile

Bitstreams conforming to the Multilayer Extended Memory 10 shall obeythe following constraints:

-   -   Referenced SPSs shall have sps_chroma_format_idc equal to 0 or        1.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   Referenced SPSs shall have sps_palette_enabled_flag equal to 0.    -   In a bitstream conforming to the Multilayer Extended Memory 10        profile, general_level_idc and sublayer_level_idc[i] for all        values of i in the referenced VPS (when available) and in the        referenced SPSs shall not be equal to 255 (which indicates level        15.5).    -   The tier and level constraints specified for the Multilayer        Extended Memory 10 profile in subclause A.4, as applicable,        shall be fulfilled.

Conformance of a bitstream to the Multilayer Extended Memory 10 profileis indicated by general_profile_idc being equal to 25. Decodersconforming to the Multilayer Main 10 profile at a specific level of aspecific tier shall be capable of decoding all bitstreams for which allof the following conditions apply:

-   -   The bitstream is indicated to conform to the Multilayer Extended        Memory 10, Multilayer Main 10, Main 10, or

Main 10 Still Picture profile.

-   -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level.

Multilayer Extended Memory 10 4:4:4 Profile

Bitstreams conforming to the Multilayer Extended Memory 10 shall obeythe following constraints:

-   -   Referenced SPSs shall have sps_chroma_format_idc in the range of        0 to 3, inclusive.    -   Referenced SPSs shall have sps_bitdepth_minus8 in the range of 0        to 2, inclusive.    -   In a bitstream conforming to the Multilayer Extended Memory 10        4:4:4 profile, general_level_idc and sublayer_level_idc[i] for        all values of i in the referenced VPS (when available) and in        the referenced SPSs shall not be equal to 255 (which indicates        level 15.5).    -   The tier and level constraints specified for the Multilayer        Extended Memory 10 profile in subclause A.4, as applicable,        shall be fulfilled.

Conformance of a bitstream to the Multilayer Extended Memory 10 4:4:4profile is indicated by general_profile_idc being equal to 57. Decodersconforming to the Multilayer Extended Memory 10 4:4:4 profile at aspecific level of a specific tier shall be capable of decoding allbitstreams for which all of the following conditions apply:

-   -   The bitstream is indicated to conform to the Multilayer Extended        Memory 10 4:4:4, Multilayer Extended

Memory 10, Multilayer Main 10 4:4:4, Multilayer Main 10, Main 10 4:4:4,Main 10, Main 10 4:4:4 Still Picture, or Main 10 Still Picture profile.

-   -   The bitstream is indicated to conform to a tier that is lower        than or equal to the specified tier.    -   The bitstream is indicated to conform to a level that is not        level 15.5 and is lower than or equal to the specified level

In this case, in one example, the variable maxDpbPicBuf, may be definedto be equal to 16 for the Multilayer Extended Memory 10 and MultilayerExtended Memory 10 4:4:4 profiles and the derivation of MaxDpbSize maybe as follows:

if (2*PicSizeMaxInSamplesY<=MaxLumaPs)

MaxDpbSize=2*maxDpbPicBuf else if (3*PicSizeMaxInSamplesY<=2*MaxLumaPs)

MaxDpbSize=3*maxDpbPicBuf/2 else

MaxDpbSize=maxDpbPicBuf where MaxLumaPs is specified in Table 7,maxDpbPicBuf is equal to 16 if the bitstream is indicated to conform tothe Multilayer Extended Memory 10 or Multilayer Extended Memory 10 4:4:4profile and equal to 8 otherwise, anddpb_max_dec_pic_buffering_minus1[Htid] is found in or derived from theapplicable dpb_parameters( ) syntax structure.

Alternatively, in another example, maxDpbPicBuf could be defined to beequal to 32 for the multilayer profiles, such as to support more thantwo layers at the maximum resolution defined by each level.

In this manner, source device 102 represents an example of a deviceconfigured to signal a syntax element indicating a level to which anoutput layer set conforms, wherein the syntax element is included in aprofile tier level syntax and a value of 112 indicates a 16K resolutionat a frame rate of 30 Hz is supported.

Referring again to FIG. 1, interface 108 may include any deviceconfigured to receive data generated by data encapsulator 107 andtransmit and/or store the data to a communications medium. Interface 108may include a network interface card, such as an Ethernet card, and mayinclude an optical transceiver, a radio frequency transceiver, or anyother type of device that can send and/or receive information. Further,interface 108 may include a computer system interface that may enable afile to be stored on a storage device. For example, interface 108 mayinclude a chipset supporting Peripheral Component Interconnect (PCI) andPeripheral Component Interconnect Express (PCIe) bus protocols,proprietary bus protocols, Universal Serial Bus (USB) protocols, I²C, orany other logical and physical structure that may be used tointerconnect peer devices.

Referring again to FIG. 1, destination device 120 includes interface122, data decapsulator 123, video decoder 124, and display 126.Interface 122 may include any device configured to receive data from acommunications medium. Interface 122 may include a network interfacecard, such as an Ethernet card, and may include an optical transceiver,a radio frequency transceiver, or any other type of device that canreceive and/or send information. Further, interface 122 may include acomputer system interface enabling a compliant video bitstream to beretrieved from a storage device. For example, interface 122 may includea chipset supporting PCI and PCIe bus protocols, proprietary busprotocols, USB protocols, I²C, or any other logical and physicalstructure that may be used to interconnect peer devices. Datadecapsulator 123 may be configured to receive and parse any of theexample syntax structures described herein.

Video decoder 124 may include any device configured to receive abitstream (e.g., a sub-bitstream extraction) and/or acceptablevariations thereof and reproduce video data therefrom. Display 126 mayinclude any device configured to display video data. Display 126 maycomprise one of a variety of display devices such as a liquid crystaldisplay (LCD), a plasma display, an organic light emitting diode (OLED)display, or another type of display. Display 126 may include a HighDefinition display or an Ultra High Definition display. It should benoted that although in the example illustrated in FIG. 1, video decoder124 is described as outputting data to display 126, video decoder 124may be configured to output video data to various types of devicesand/or sub-components thereof. For example, video decoder 124 may beconfigured to output video data to any communication medium, asdescribed herein.

FIG. 6 is a block diagram illustrating an example of a video decoderthat may be configured to decode video data according to one or moretechniques of this disclosure (e.g., the decoding process forreference-picture list construction described above). In one example,video decoder 600 may be configured to decode transform data andreconstruct residual data from transform coefficients based on decodedtransform data. Video decoder 600 may be configured to perform intraprediction decoding and inter prediction decoding and, as such, may bereferred to as a hybrid decoder. Video decoder 600 may be configured toparse any combination of the syntax elements described above in Tables1-11. Video decoder 600 may decode a picture based on or according tothe processes described above, and further based on parsed values inTables 1-11.

In the example illustrated in FIG. 6, video decoder 600 includes anentropy decoding unit 602, inverse quantization unit 604, inversetransform coefficient processing unit 606, intra prediction processingunit 608, inter prediction processing unit 610, summer 612, post filterunit 614, and reference buffer 616. Video decoder 600 may be configuredto decode video data in a manner consistent with a video coding system.It should be noted that although example video decoder 600 isillustrated as having distinct functional blocks, such an illustrationis for descriptive purposes and does not limit video decoder 600 and/orsub-components thereof to a particular hardware or softwarearchitecture. Functions of video decoder 600 may be realized using anycombination of hardware, firmware, and/or software implementations.

As illustrated in FIG. 6, entropy decoding unit 602 receives an entropyencoded bitstream. Entropy decoding unit 602 may be configured to decodesyntax elements and quantized coefficients from the bitstream accordingto a process reciprocal to an entropy encoding process. Entropy decodingunit 602 may be configured to perform entropy decoding according any ofthe entropy coding techniques described above. Entropy decoding unit 602may determine values for syntax elements in an encoded bitstream in amanner consistent with a video coding standard. As illustrated in FIG.6, entropy decoding unit 602 may determine a quantization parameter,quantized coefficient values, transform data, and prediction data from abitstream. In the example, illustrated in FIG. 6, inverse quantizationunit 604 and inverse transform coefficient processing unit 606 receivequantized coefficient values from entropy decoding unit 602 and outputreconstructed residual data.

Referring again to FIG. 6, reconstructed residual data may be providedto summer 612. Summer 612 may add reconstructed residual data to apredictive video block and generate reconstructed video data. Apredictive video block may be determined according to a predictive videotechnique (i.e., intra prediction and inter frame prediction). Intraprediction processing unit 608 may be configured to receive intraprediction syntax elements and retrieve a predictive video block fromreference buffer 616. Reference buffer 616 may include a memory deviceconfigured to store one or more frames of video data. Intra predictionsyntax elements may identify an intra prediction mode, such as the intraprediction modes described above. Inter prediction processing unit 610may receive inter prediction syntax elements and generate motion vectorsto identify a prediction block in one or more reference frames stored inreference buffer 616. Inter prediction processing unit 610 may producemotion compensated blocks, possibly performing interpolation based oninterpolation filters. Identifiers for interpolation filters to be usedfor motion estimation with sub-pixel precision may be included in thesyntax elements. Inter prediction processing unit 610 may useinterpolation filters to calculate interpolated values for sub-integerpixels of a reference block. Post filter unit 614 may be configured toperform filtering on reconstructed video data. For example, post filterunit 614 may be configured to perform deblocking and/or Sample AdaptiveOffset (SAO) filtering, e.g., based on parameters specified in abitstream. Further, it should be noted that in some examples, postfilter unit 614 may be configured to perform proprietary discretionaryfiltering (e.g., visual enhancements, such as, mosquito noisereduction). As illustrated in FIG. 6, a reconstructed video block may beoutput by video decoder 600. In this manner, video decoder 600represents an example of a device configured to receive profile tierlevel syntax, parse a syntax element from the profile tier level syntaxindicating a level to which an output layer set conforms, wherein avalue of 112 indicates a 16K resolution at a frame rate of 30 Hz issupported and perform video decoding based on the indicated level.

In one or more examples, the functions described may be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions may be stored on or transmitted over as oneor more instructions or code on a computer-readable medium and executedby a hardware-based processing unit. Computer-readable media may includecomputer-readable storage media, which corresponds to a tangible mediumsuch as data storage media, or communication media including any mediumthat facilitates transfer of a computer program from one place toanother, e.g., according to a communication protocol. In this manner,computer-readable media generally may correspond to (1) tangiblecomputer-readable storage media which is non-transitory or (2) acommunication medium such as a signal or carrier wave. Data storagemedia may be any available media that can be accessed by one or morecomputers or one or more processors to retrieve instructions, codeand/or data structures for implementation of the techniques described inthis disclosure. A computer program product may include acomputer-readable medium.

By way of example, and not limitation, such computer-readable storagemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage, or other magnetic storage devices, flashmemory, or any other medium that can be used to store desired programcode in the form of instructions or data structures and that can beaccessed by a computer. Also, any connection is properly termed acomputer-readable medium. For example, if instructions are transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, digital subscriber line (DSL), orwireless technologies such as infrared, radio, and microwave, then thecoaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. It should be understood, however, thatcomputer-readable storage media and data storage media do not includeconnections, carrier waves, signals, or other transitory media, but areinstead directed to non-transitory, tangible storage media. Disk anddisc, as used herein, includes compact disc (CD), laser disc, opticaldisc, digital versatile disc (DVD), floppy disk and Blu-ray disc wheredisks usually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

Instructions may be executed by one or more processors, such as one ormore digital signal processors (DSPs), general purpose microprocessors,application specific integrated circuits (ASICs), field programmablelogic arrays (FPGAs), or other equivalent integrated or discrete logiccircuitry. Accordingly, the term “processor,” as used herein may referto any of the foregoing structure or any other structure suitable forimplementation of the techniques described herein. In addition, in someaspects, the functionality described herein may be provided withindedicated hardware and/or software modules configured for encoding anddecoding, or incorporated in a combined codec. Also, the techniquescould be fully implemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide varietyof devices or apparatuses, including a wireless handset, an integratedcircuit (IC) or a set of ICs (e.g., a chip set). Various components,modules, or units are described in this disclosure to emphasizefunctional aspects of devices configured to perform the disclosedtechniques, but do not necessarily require realization by differenthardware units. Rather, as described above, various units may becombined in a codec hardware unit or provided by a collection ofinteroperative hardware units, including one or more processors asdescribed above, in conjunction with suitable software and/or firmware.

Moreover, each functional block or various features of the base stationdevice and the terminal device used in each of the aforementionedembodiments may be implemented or executed by a circuitry, which istypically an integrated circuit or a plurality of integrated circuits.The circuitry designed to execute the functions described in the presentspecification may comprise a general-purpose processor, a digital signalprocessor (DSP), an application specific or general applicationintegrated circuit (ASIC), a field programmable gate array (FPGA), orother programmable logic devices, discrete gates or transistor logic, ora discrete hardware component, or a combination thereof. Thegeneral-purpose processor may be a microprocessor, or alternatively, theprocessor may be a conventional processor, a controller, amicrocontroller or a state machine. The general-purpose processor oreach circuit described above may be configured by a digital circuit ormay be configured by an analogue circuit. Further, when a technology ofmaking into an integrated circuit superseding integrated circuits at thepresent time appears due to advancement of a semiconductor technology,the integrated circuit by this technology is also able to be used.

Various examples have been described. These and other examples arewithin the scope of the following claims.

What is claimed is:
 1. A method of decoding video data, the methodcomprising: receiving profile tier level syntax; parsing a syntaxelement, from the profile tier level syntax, indicating a level to whichan output layer set conforms, wherein a value of 105 indicates a levelwhere a maximum luma sample rate of 4812963840 samples per second issupported; and performing video decoding based on the indicated level.2. The method of claim 1, wherein performing video decoding based on theindicated level includes setting a decoded picture buffer size.
 3. Adevice comprising one or more processors configured to: receive profiletier level syntax; parse a syntax element, from the profile tier levelsyntax, indicating a level to which an output layer set conforms,wherein a value of 105 indicates a level where a maximum luma samplerate of 4812963840 samples per second is supported; and perform videodecoding based on the indicated level.
 4. The device of claim 3, whereinthe device includes a video decoder.
 5. A non-transitorycomputer-readable storage medium comprising instructions stored thereonthat, when executed, cause one or more processors of a device to:receive profile tier level syntax; parse a syntax element, from theprofile tier level syntax, indicating a level to which an output layerset conforms, wherein a value of 105 indicates a level where a maximumluma sample rate of 4812963840 samples per second is supported; andperform video decoding based on the indicated level.